Change the EOT handling on TX.

This reverts commit 8a1ab88c3a.

AX25Defines.h

@@ -0,0 +1,36 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if !defined(AX25DEFINES_H)
+#define  AX25DEFINES_H
+
+const uint8_t AX25_RADIO_SYMBOL_LENGTH = 20U;      // At 24 kHz sample rate
+
+const uint8_t AX25_FRAME_START = 0x7EU;
+const uint8_t AX25_FRAME_END   = 0x7EU;
+const uint8_t AX25_FRAME_ABORT = 0xFEU;
+
+const uint8_t AX25_MAX_ONES    = 5U;
+
+const uint16_t AX25_MIN_FRAME_LENGTH = 17U;        // Callsign (7) + Callsign (7) + Control (1) + Checksum (2)
+
+const uint16_t AX25_MAX_FRAME_LENGTH = 330U;       // Callsign (7) + Callsign (7) + 8 Digipeaters (56) +
+                                                   // Control (1) + PID (1) + Data (256) + Checksum (2)
+
+#endif
+

AX25Demodulator.cpp

@@ -0,0 +1,319 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright 2015-2019 Mobilinkd LLC <[email protected]>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_AX25)
+
+#include "Globals.h"
+#include "AX25Demodulator.h"
+#include "AX25Defines.h"
+
+const float32_t SAMPLE_RATE = 24000.0F;
+const float32_t SYMBOL_RATE = 1200.0F;
+
+const uint16_t DELAY_LEN = 11U;
+
+const float32_t SAMPLES_PER_SYMBOL = SAMPLE_RATE / SYMBOL_RATE;
+const float32_t PLL_LIMIT          = SAMPLES_PER_SYMBOL / 2.0F;
+
+const uint32_t LPF_FILTER_LEN = 48U;
+
+q15_t LPF_FILTER_COEFFS[] = {
+    -2,   -8,  -17,  -28,  -40,  -47,  -47,  -34,
+    -5,   46,  122,  224,  354,  510,  689,  885,
+  1092, 1302, 1506, 1693, 1856, 1987, 2077, 2124,
+  2124, 2077, 1987, 1856, 1693, 1506, 1302, 1092,
+  885,  689,  510,  354,  224,  122,   46,    -5,
+  -34,  -47,  -47,  -40,  -28,  -17,   -8,    -2
+};
+
+// Lock low-pass filter taps (80Hz Bessel)
+// scipy.signal:
+//      b, a = bessel(4, [80.0/(1200/2)], 'lowpass')
+//
+const uint8_t PLL_IIR_SIZE = 5U;
+
+const float32_t PLL_LOCK_B[] = {
+    1.077063e-03,4.308253e-03,6.462379e-03,4.308253e-03,1.077063e-03};
+
+const float32_t PLL_LOCK_A[] = {
+    1.000000e+00,-2.774567e+00,2.962960e+00,-1.437990e+00,2.668296e-01};
+
+// 64 Hz loop filter.
+// scipy.signal:
+//      loop_coeffs = firwin(9, [64.0/(1200/2)], width = None,
+//          pass_zero = True, scale = True, window='hann')
+//
+const uint32_t PLL_FILTER_LEN = 7U;
+
+float32_t PLL_FILTER_COEFFS[] = {3.196252e-02F, 1.204223e-01F, 2.176819e-01F, 2.598666e-01F, 2.176819e-01F, 1.204223e-01F, 3.196252e-02F};
+
+CAX25Demodulator::CAX25Demodulator(int8_t n) :
+m_frame(),
+m_twist(n),
+m_lpfFilter(),
+m_lpfState(),
+m_delayLine(NULL),
+m_delayPos(0U),
+m_nrziState(false),
+m_pllFilter(),
+m_pllState(),
+m_pllLast(false),
+m_pllBits(1U),
+m_pllCount(0.0F),
+m_pllJitter(0.0F),
+m_pllDCD(false),
+m_iirHistory(),
+m_hdlcOnes(0U),
+m_hdlcFlag(false),
+m_hdlcBuffer(0U),
+m_hdlcBits(0U),
+m_hdlcState(AX25_IDLE)
+{
+  m_delayLine = new bool[DELAY_LEN];
+
+  m_lpfFilter.numTaps = LPF_FILTER_LEN;
+  m_lpfFilter.pState  = m_lpfState;
+  m_lpfFilter.pCoeffs = LPF_FILTER_COEFFS;
+
+  m_pllFilter.numTaps = PLL_FILTER_LEN;
+  m_pllFilter.pState  = m_pllState;
+  m_pllFilter.pCoeffs = PLL_FILTER_COEFFS;
+
+  for (uint8_t i = 0U; i < PLL_IIR_SIZE; i++)
+    m_iirHistory[i] = 0.0F;
+}
+
+bool CAX25Demodulator::process(q15_t* samples, uint8_t length, CAX25Frame& frame)
+{
+  bool result = false;
+
+  q15_t fa[RX_BLOCK_SIZE];
+  m_twist.process(samples, fa, RX_BLOCK_SIZE);
+
+  int16_t buffer[RX_BLOCK_SIZE];
+  for (uint8_t i = 0; i < length; i++) {
+      bool   level = (fa[i] >= 0);
+      bool delayed = delay(level);
+      buffer[i] = (int16_t(level ^ delayed) << 1) - 1;
+  }
+
+  q15_t fc[RX_BLOCK_SIZE];
+  ::arm_fir_fast_q15(&m_lpfFilter, buffer, fc, RX_BLOCK_SIZE);
+
+  for (uint8_t i = 0; i < length; i++) {
+    bool bit = fc[i] >= 0;
+    bool sample = PLL(bit);
+
+    if (sample) {
+      // We will only ever get one frame because there are
+      // not enough bits in a block for more than one.
+      if (result) {
+        HDLC(NRZI(bit));
+      } else {
+        result = HDLC(NRZI(bit));
+        if (result) {
+          // Copy the frame data.
+          ::memcpy(frame.m_data, m_frame.m_data, AX25_MAX_PACKET_LEN);
+          frame.m_length = m_frame.m_length;
+          frame.m_fcs    = m_frame.m_fcs;
+          m_frame.m_length = 0U;
+        }
+      }
+    }
+  }
+
+  return result;
+}
+
+bool CAX25Demodulator::delay(bool b)
+{
+  bool r = m_delayLine[m_delayPos];
+
+  m_delayLine[m_delayPos++] = b;
+
+  if (m_delayPos >= DELAY_LEN)
+    m_delayPos = 0U;
+
+  return r;
+}
+
+bool CAX25Demodulator::NRZI(bool b)
+{
+  bool result = (b == m_nrziState);
+
+  m_nrziState = b;
+
+  return result;
+}
+
+bool CAX25Demodulator::PLL(bool input)
+{
+  bool sample = false;
+		
+  if (input != m_pllLast || m_pllBits > 16U) {
+    // Record transition.
+    m_pllLast = input;
+
+    if (m_pllCount > PLL_LIMIT)
+      m_pllCount -= SAMPLES_PER_SYMBOL;
+
+    float32_t adjust = m_pllBits > 16U ? 5.0F : 0.0F;
+    float32_t offset = m_pllCount / float32_t(m_pllBits);
+    float32_t jitter;
+    ::arm_fir_f32(&m_pllFilter, &offset, &jitter, 1U);
+
+    float32_t absOffset = adjust;
+    if (offset < 0.0F)
+      absOffset -= offset;
+    else
+      absOffset += offset;
+    m_pllJitter = iir(absOffset);
+
+    m_pllCount -= jitter / 2.0F;
+    m_pllBits = 1U;
+  } else {
+    if (m_pllCount > PLL_LIMIT) {
+      sample = true;
+      m_pllCount -= SAMPLES_PER_SYMBOL;
+      m_pllBits++;
+    }
+  }
+
+  m_pllCount += 1.0F;
+
+  return sample;
+}
+
+bool CAX25Demodulator::HDLC(bool b)
+{
+  if (m_hdlcOnes == AX25_MAX_ONES) {
+    if (b) {
+      // flag byte
+      m_hdlcFlag = true;
+    } else {
+      // bit stuffing...
+      m_hdlcFlag = false;
+      m_hdlcOnes = 0U;
+      return false;
+    }
+  }
+
+  m_hdlcBuffer >>= 1;
+  m_hdlcBuffer |= b ? 128U : 0U;
+  m_hdlcBits++;                      // Free-running until Sync byte.
+
+  if (b)
+    m_hdlcOnes++;
+  else
+    m_hdlcOnes = 0U;
+
+  if (m_hdlcFlag) {
+    bool result = false;
+
+    switch (m_hdlcBuffer) {
+      case AX25_FRAME_END:
+        if (m_frame.m_length >= AX25_MIN_FRAME_LENGTH) {
+          result = m_frame.checkCRC();
+          if (!result)
+              m_frame.m_length = 0U;
+        } else {
+            m_frame.m_length = 0U;
+        }
+        m_hdlcState = AX25_SYNC;
+        m_hdlcFlag = false;
+        m_hdlcBits = 0U;
+        break;
+
+      case AX25_FRAME_ABORT:
+        // Frame aborted
+        m_frame.m_length = 0U;
+        m_hdlcState = AX25_IDLE;
+        m_hdlcFlag = false;
+        m_hdlcBits = 0U;
+        break;
+
+      default:
+        break;
+    }
+
+    return result;
+  }
+
+  switch (m_hdlcState) {
+    case AX25_IDLE:
+      break;
+
+    case AX25_SYNC:
+      if (m_hdlcBits == 8U) {    // 8th bit.
+        // Start of frame data.
+        m_hdlcState = AX25_RECEIVE;
+        m_frame.append(m_hdlcBuffer);
+        m_hdlcBits = 0U;
+      }
+      break;
+
+    case AX25_RECEIVE:
+      if (m_hdlcBits == 8U) {    // 8th bit.
+        m_frame.append(m_hdlcBuffer);
+        m_hdlcBits = 0U;
+      }
+      break;
+
+    default:
+      break;
+  }
+
+  return false;
+}
+
+void CAX25Demodulator::setTwist(int8_t n)
+{
+  m_twist.setTwist(n);
+}
+
+bool CAX25Demodulator::isDCD()
+{
+  if (m_pllJitter <= (SAMPLES_PER_SYMBOL * 0.03F))
+    m_pllDCD = true;
+  else if (m_pllJitter >= (SAMPLES_PER_SYMBOL * 0.15F))
+    m_pllDCD = false;
+
+  return m_pllDCD;
+}
+
+float32_t CAX25Demodulator::iir(float32_t input)
+{
+  for (int8_t i = int8_t(PLL_IIR_SIZE) - 1; i != 0; i--)
+    m_iirHistory[i] = m_iirHistory[i - 1];
+
+  m_iirHistory[0] = input;
+  for (uint8_t i = 1U; i < PLL_IIR_SIZE; i++)
+    m_iirHistory[0] -= PLL_LOCK_A[i] * m_iirHistory[i];
+
+  float32_t result = 0.0F;
+  for (uint8_t i = 0U; i < PLL_IIR_SIZE; i++)
+    result += PLL_LOCK_B[i] * m_iirHistory[i];
+
+  return result;
+}
+
+#endif
+

AX25Demodulator.h

@@ -0,0 +1,77 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_AX25)
+
+#if !defined(AX25Demodulator_H)
+#define  AX25Demodulator_H
+
+#include "AX25Frame.h"
+#include "AX25Twist.h"
+
+enum AX25_STATE {
+  AX25_IDLE,
+  AX25_SYNC,
+  AX25_RECEIVE
+};
+
+class CAX25Demodulator {
+public:
+  CAX25Demodulator(int8_t n);
+
+  bool process(q15_t* samples, uint8_t length, CAX25Frame& frame);
+
+  void setTwist(int8_t n);
+
+  bool isDCD();
+
+private:
+  CAX25Frame           m_frame;
+  CAX25Twist           m_twist;
+  arm_fir_instance_q15 m_lpfFilter;
+  q15_t                m_lpfState[70U];     // NoTaps + BlockSize - 1, 48 + 20 - 1 plus some spare
+  bool*                m_delayLine;
+  uint16_t             m_delayPos;
+  bool                 m_nrziState;
+  arm_fir_instance_f32 m_pllFilter;
+  float32_t            m_pllState[20U];     // NoTaps + BlockSize - 1, 7 + 1 - 1 plus some spare
+  bool                 m_pllLast;
+  uint8_t              m_pllBits;
+  float32_t            m_pllCount;
+  float32_t            m_pllJitter;
+  bool                 m_pllDCD;
+  float32_t            m_iirHistory[5U];
+  uint16_t             m_hdlcOnes;
+  bool                 m_hdlcFlag;
+  uint16_t             m_hdlcBuffer;
+  uint16_t             m_hdlcBits;
+  AX25_STATE           m_hdlcState;
+
+  bool delay(bool b);
+  bool NRZI(bool b);
+  bool PLL(bool b);
+  bool HDLC(bool b);
+  float32_t iir(float32_t input);
+};
+
+#endif
+
+#endif
+

AX25Frame.cpp

@@ -0,0 +1,127 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_AX25)
+
+#include "Globals.h"
+#include "AX25Frame.h"
+
+const uint16_t CCITT_TABLE[] = {
+	0x0000,0x1189,0x2312,0x329b,0x4624,0x57ad,0x6536,0x74bf,
+	0x8c48,0x9dc1,0xaf5a,0xbed3,0xca6c,0xdbe5,0xe97e,0xf8f7,
+	0x1081,0x0108,0x3393,0x221a,0x56a5,0x472c,0x75b7,0x643e,
+	0x9cc9,0x8d40,0xbfdb,0xae52,0xdaed,0xcb64,0xf9ff,0xe876,
+	0x2102,0x308b,0x0210,0x1399,0x6726,0x76af,0x4434,0x55bd,
+	0xad4a,0xbcc3,0x8e58,0x9fd1,0xeb6e,0xfae7,0xc87c,0xd9f5,
+	0x3183,0x200a,0x1291,0x0318,0x77a7,0x662e,0x54b5,0x453c,
+	0xbdcb,0xac42,0x9ed9,0x8f50,0xfbef,0xea66,0xd8fd,0xc974,
+	0x4204,0x538d,0x6116,0x709f,0x0420,0x15a9,0x2732,0x36bb,
+	0xce4c,0xdfc5,0xed5e,0xfcd7,0x8868,0x99e1,0xab7a,0xbaf3,
+	0x5285,0x430c,0x7197,0x601e,0x14a1,0x0528,0x37b3,0x263a,
+	0xdecd,0xcf44,0xfddf,0xec56,0x98e9,0x8960,0xbbfb,0xaa72,
+	0x6306,0x728f,0x4014,0x519d,0x2522,0x34ab,0x0630,0x17b9,
+	0xef4e,0xfec7,0xcc5c,0xddd5,0xa96a,0xb8e3,0x8a78,0x9bf1,
+	0x7387,0x620e,0x5095,0x411c,0x35a3,0x242a,0x16b1,0x0738,
+	0xffcf,0xee46,0xdcdd,0xcd54,0xb9eb,0xa862,0x9af9,0x8b70,
+	0x8408,0x9581,0xa71a,0xb693,0xc22c,0xd3a5,0xe13e,0xf0b7,
+	0x0840,0x19c9,0x2b52,0x3adb,0x4e64,0x5fed,0x6d76,0x7cff,
+	0x9489,0x8500,0xb79b,0xa612,0xd2ad,0xc324,0xf1bf,0xe036,
+	0x18c1,0x0948,0x3bd3,0x2a5a,0x5ee5,0x4f6c,0x7df7,0x6c7e,
+	0xa50a,0xb483,0x8618,0x9791,0xe32e,0xf2a7,0xc03c,0xd1b5,
+	0x2942,0x38cb,0x0a50,0x1bd9,0x6f66,0x7eef,0x4c74,0x5dfd,
+	0xb58b,0xa402,0x9699,0x8710,0xf3af,0xe226,0xd0bd,0xc134,
+	0x39c3,0x284a,0x1ad1,0x0b58,0x7fe7,0x6e6e,0x5cf5,0x4d7c,
+	0xc60c,0xd785,0xe51e,0xf497,0x8028,0x91a1,0xa33a,0xb2b3,
+	0x4a44,0x5bcd,0x6956,0x78df,0x0c60,0x1de9,0x2f72,0x3efb,
+	0xd68d,0xc704,0xf59f,0xe416,0x90a9,0x8120,0xb3bb,0xa232,
+	0x5ac5,0x4b4c,0x79d7,0x685e,0x1ce1,0x0d68,0x3ff3,0x2e7a,
+	0xe70e,0xf687,0xc41c,0xd595,0xa12a,0xb0a3,0x8238,0x93b1,
+	0x6b46,0x7acf,0x4854,0x59dd,0x2d62,0x3ceb,0x0e70,0x1ff9,
+	0xf78f,0xe606,0xd49d,0xc514,0xb1ab,0xa022,0x92b9,0x8330,
+	0x7bc7,0x6a4e,0x58d5,0x495c,0x3de3,0x2c6a,0x1ef1,0x0f78 };
+
+CAX25Frame::CAX25Frame(const uint8_t* data, uint16_t length) :
+m_data(),
+m_length(0U),
+m_fcs(0U)
+{
+  for (uint16_t i = 0U; i < length && i < (AX25_MAX_PACKET_LEN - 2U); i++)
+    m_data[m_length++] = data[i];
+}
+
+CAX25Frame::CAX25Frame() :
+m_data(),
+m_length(0U),
+m_fcs(0U)
+{
+}
+
+bool CAX25Frame::append(uint16_t c)
+{
+  if (m_length == AX25_MAX_PACKET_LEN)
+    return false;
+
+  m_data[m_length++] = uint8_t(c);
+
+  return true;
+}
+
+bool CAX25Frame::checkCRC()
+{
+  union {
+    uint16_t crc16;
+    uint8_t  crc8[2U];
+  };
+
+  crc16 = 0xFFFFU;
+  for (uint16_t i = 0U; i < (m_length - 2U); i++)
+    crc16 = uint16_t(crc8[1U]) ^ CCITT_TABLE[crc8[0U] ^ m_data[i]];
+
+  crc16 = ~crc16;
+
+  if (crc8[0U] == m_data[m_length - 2U] && crc8[1U] == m_data[m_length - 1U]) {
+    m_fcs = crc16;
+    return true;
+  } else {
+    return false;
+  }
+}
+
+void CAX25Frame::addCRC()
+{
+  union {
+    uint16_t crc16;
+    uint8_t  crc8[2U];
+  };
+
+  crc16 = 0xFFFFU;
+  for (uint16_t i = 0U; i < m_length; i++)
+    crc16 = uint16_t(crc8[1U]) ^ CCITT_TABLE[crc8[0U] ^ m_data[i]];
+
+  crc16 = ~crc16;
+
+  m_fcs = crc16;
+
+  m_data[m_length++] = crc8[0U];
+  m_data[m_length++] = crc8[1U];
+}
+
+#endif
+

AX25Frame.h

@@ -0,0 +1,47 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_AX25)
+
+#if !defined(AX25Frame_H)
+#define  AX25Frame_H
+
+const uint16_t AX25_MAX_PACKET_LEN = 300U;
+
+class CAX25Frame {
+public:
+  CAX25Frame(const uint8_t* data, uint16_t length);
+  CAX25Frame();
+
+  bool append(uint16_t c);
+
+  bool checkCRC();
+
+  void addCRC();
+
+  uint8_t  m_data[AX25_MAX_PACKET_LEN];
+  uint16_t m_length;
+  uint16_t m_fcs;
+};
+
+#endif
+
+#endif
+

AX25RX.cpp

@@ -0,0 +1,211 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_AX25)
+
+#include "Globals.h"
+#include "AX25RX.h"
+
+/*
+ * Generated with Scipy Filter, 152 coefficients, 1100-2300Hz bandpass,
+ * Hann window, starting and ending 0 value coefficients removed.
+ *
+ * np.array(
+ *  firwin2(152,
+ *      [
+ *          0.0,
+ *          1000.0/(sample_rate/2),
+ *          1100.0/(sample_rate/2),
+ *          2350.0/(sample_rate/2),
+ *          2500.0/(sample_rate/2),
+ *          1.0
+ *      ],
+ *      [0,0,1,1,0,0],
+ *      antisymmetric = False,
+ *      window='hann') * 32768,
+ *  dtype=int)[10:-10]
+ */
+
+const uint32_t FILTER_LEN = 130U;
+
+q15_t FILTER_COEFFS[] = {
+      5,    12,    18,    21,   19,   11,    -2,   -15,   -25,   -27,
+    -21,   -11,    -3,    -5,  -19,  -43,   -69,   -83,   -73,   -35,
+     27,    98,   155,   180,  163,  109,    39,   -20,   -45,   -26,
+     23,    74,    89,    39,  -81, -247,  -407,  -501,  -480,  -334,
+    -92,   175,   388,   479,  429,  275,    99,     5,    68,   298,
+    626,   913,   994,   740,  115, -791, -1770, -2544, -2847, -2509,
+  -1527,   -76,  1518,  2875, 3653, 3653,  2875,  1518,   -76, -1527,
+  -2509, -2847, -2544, -1770, -791,  115,   740,   994,   913,   626,
+    298,    68,     5,    99,  275,  429,   479,   388,   175,   -92,
+   -334,  -480,  -501,  -407, -247,  -81,    39,    89,    74,    23,
+    -26,   -45,   -20,    39,  109,  163,   180,   155,    98,    27,
+    -35,   -73,   -83,   -69,  -43,  -19,    -5,    -3,   -11,   -21,
+    -27,   -25,   -15,    -2,   11,   19,    21,    18,    12,     5
+};
+
+CAX25RX::CAX25RX() :
+m_filter(),
+m_state(),
+m_demod1(3),
+m_demod2(6),
+m_demod3(9),
+m_lastFCS(0U),
+m_count(0U),
+m_slotTime(30U),
+m_slotCount(0U),
+m_pPersist(128U),
+m_dcd(false),
+m_canTX(false),
+m_x(1U),
+m_a(0xB7U),
+m_b(0x73U),
+m_c(0xF6U)
+{
+  m_filter.numTaps = FILTER_LEN;
+  m_filter.pState  = m_state;
+  m_filter.pCoeffs = FILTER_COEFFS;
+
+  initRand();
+}
+
+void CAX25RX::samples(q15_t* samples, uint8_t length)
+{
+  q15_t output[RX_BLOCK_SIZE];
+  ::arm_fir_fast_q15(&m_filter, samples, output, RX_BLOCK_SIZE);
+
+  m_count++;
+
+  CAX25Frame frame;
+
+  bool ret = m_demod1.process(output, length, frame);
+  if (ret) {
+    if (frame.m_fcs != m_lastFCS || m_count > 2U) {
+      m_lastFCS = frame.m_fcs;
+      m_count   = 0U;
+      serial.writeAX25Data(frame.m_data, frame.m_length - 2U);
+    }
+    DEBUG1("Decoder 1 reported");
+  }
+
+  ret = m_demod2.process(output, length, frame);
+  if (ret) {
+    if (frame.m_fcs != m_lastFCS || m_count > 2U) {
+      m_lastFCS = frame.m_fcs;
+      m_count   = 0U;
+      serial.writeAX25Data(frame.m_data, frame.m_length - 2U);
+    }
+    DEBUG1("Decoder 2 reported");
+  }
+
+  ret = m_demod3.process(output, length, frame);
+  if (ret) {
+    if (frame.m_fcs != m_lastFCS || m_count > 2U) {
+      m_lastFCS = frame.m_fcs;
+      m_count   = 0U;
+      serial.writeAX25Data(frame.m_data, frame.m_length - 2U);
+    }
+    DEBUG1("Decoder 3 reported");
+  }
+
+  m_slotCount += RX_BLOCK_SIZE;
+  if (m_slotCount >= m_slotTime) {
+    m_slotCount = 0U;
+
+    bool dcd1 = m_demod1.isDCD();
+    bool dcd2 = m_demod2.isDCD();
+    bool dcd3 = m_demod3.isDCD();
+    
+    if (dcd1 || dcd2 || dcd3) {
+      if (!m_dcd) {
+        io.setDecode(true);
+        io.setADCDetection(true);
+        m_dcd = true;
+      }
+
+      m_canTX = false;
+    } else {
+      if (m_dcd) {
+        io.setDecode(false);
+        io.setADCDetection(false);
+        m_dcd = false;
+      }
+
+      m_canTX = m_pPersist >= rand();
+    }
+  }
+}
+
+bool CAX25RX::canTX() const
+{
+  return m_canTX;
+}
+
+void CAX25RX::setParams(int8_t twist, uint8_t slotTime, uint8_t pPersist)
+{
+  m_demod1.setTwist(twist - 3);
+  m_demod2.setTwist(twist);
+  m_demod3.setTwist(twist + 3);
+
+  m_slotTime = slotTime * 240U;    // Slot time in samples
+  m_pPersist = pPersist;
+}
+
+// Taken from https://www.electro-tech-online.com/threads/ultra-fast-pseudorandom-number-generator-for-8-bit.124249/
+//X ABC Algorithm Random Number Generator for 8-Bit Devices:
+//This is a small PRNG, experimentally verified to have at least a 50 million byte period
+//by generating 50 million bytes and observing that there were no overapping sequences and repeats.
+//This generator passes serial correlation, entropy , Monte Carlo Pi value, arithmetic mean,
+//And many other statistical tests. This generator may have a period of up to 2^32, but this has
+//not been verified.
+//
+// By XORing 3 bytes into the a,b, and c registers, you can add in entropy from 
+//an external source easily.
+//
+//This generator is free to use, but is not suitable for cryptography due to its short period(by //cryptographic standards) and simple construction. No attempt was made to make this generator 
+// suitable for cryptographic use.
+//
+//Due to the use of a constant counter, the generator should be resistant to latching up.
+//A significant performance gain is had in that the x variable is only ever incremented.
+//
+//Only 4 bytes of ram are needed for the internal state, and generating a byte requires 3 XORs , //2 ADDs, one bit shift right , and one increment. Difficult or slow operations like multiply, etc 
+//were avoided for maximum speed on ultra low power devices.
+
+
+void CAX25RX::initRand() //Can also be used to seed the rng with more entropy during use.
+{
+  m_a = (m_a ^ m_c ^ m_x);
+  m_b = (m_b + m_a);
+  m_c = (m_c + (m_b >> 1) ^ m_a);
+}
+
+uint8_t CAX25RX::rand()
+{
+  m_x++;                           //x is incremented every round and is not affected by any other variable
+
+  m_a = (m_a ^ m_c ^ m_x);         //note the mix of addition and XOR
+  m_b = (m_b + m_a);               //And the use of very few instructions
+  m_c = (m_c + (m_b >> 1) ^ m_a);  //the right shift is to ensure that high-order bits from b can affect  
+
+  return uint8_t(m_c);             //low order bits of other variables
+}
+
+#endif
+

AX25RX.h

@@ -0,0 +1,63 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_AX25)
+
+#if !defined(AX25RX_H)
+#define  AX25RX_H
+
+#include "AX25Demodulator.h"
+
+class CAX25RX {
+public:
+  CAX25RX();
+
+  void samples(q15_t* samples, uint8_t length);
+
+  void setParams(int8_t twist, uint8_t slotTime, uint8_t pPersist);
+
+  bool canTX() const;
+
+private:
+  arm_fir_instance_q15 m_filter;
+  q15_t                m_state[160U];    // NoTaps + BlockSize - 1, 130 + 20 - 1 plus some spare
+  CAX25Demodulator     m_demod1;
+  CAX25Demodulator     m_demod2;
+  CAX25Demodulator     m_demod3;
+  uint16_t             m_lastFCS;
+  uint32_t             m_count;
+  uint32_t             m_slotTime;
+  uint32_t             m_slotCount;
+  uint8_t              m_pPersist;
+  bool                 m_dcd;
+  bool                 m_canTX;
+  uint8_t              m_x;
+  uint8_t              m_a;
+  uint8_t              m_b;
+  uint8_t              m_c;
+  
+  void initRand();
+  uint8_t rand();
+};
+
+#endif
+
+#endif
+

AX25TX.cpp

@@ -0,0 +1,191 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_AX25)
+
+#include "Globals.h"
+#include "AX25TX.h"
+
+#include "AX25Defines.h"
+#include "AX25Frame.h"
+
+
+const uint8_t START_FLAG[] = { AX25_FRAME_START };
+const uint8_t END_FLAG[]   = { AX25_FRAME_END };
+
+const uint8_t BIT_MASK_TABLE1[] = { 0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U };
+
+#define WRITE_BIT1(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE1[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE1[(i)&7])
+#define READ_BIT1(p,i)    (p[(i)>>3] & BIT_MASK_TABLE1[(i)&7])
+
+const uint8_t BIT_MASK_TABLE2[] = { 0x01U, 0x02U, 0x04U, 0x08U, 0x10U, 0x20U, 0x40U, 0x80U };
+
+#define WRITE_BIT2(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE2[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE2[(i)&7])
+#define READ_BIT2(p,i)    (p[(i)>>3] & BIT_MASK_TABLE2[(i)&7])
+
+const uint16_t AUDIO_TABLE_LEN = 120U;
+
+const q15_t AUDIO_TABLE_DATA[] = {
+  0, 214, 428, 641, 851, 1060, 1265, 1468, 1666, 1859, 2048, 2230, 2407, 2577, 2740, 2896, 3043, 3182, 3313, 3434, 3546, 3649,
+  3741, 3823, 3895, 3955, 4006, 4045, 4073, 4089, 4095, 4089, 4073, 4045, 4006, 3955, 3895, 3823, 3741, 3649, 3546, 3434, 3313,
+  3182, 3043, 2896, 2740, 2577, 2407, 2230, 2048, 1859, 1666, 1468, 1265, 1060, 851, 641, 428, 214, 0, -214, -428, -641, -851,
+  -1060, -1265, -1468, -1666, -1859, -2047, -2230, -2407, -2577, -2740, -2896, -3043, -3182, -3313, -3434, -3546, -3649, -3741,
+  -3823, -3895, -3955, -4006, -4045, -4073, -4089, -4095, -4089, -4073, -4045, -4006, -3955, -3895, -3823, -3741, -3649, -3546,
+  -3434, -3313, -3182, -3043, -2896, -2740, -2577, -2407, -2230, -2047, -1859, -1666, -1468, -1265, -1060, -851, -641, -428, -214
+};
+
+CAX25TX::CAX25TX() :
+m_poBuffer(),
+m_poLen(0U),
+m_poPtr(0U),
+m_txDelay(360U),
+m_tablePtr(0U),
+m_nrzi(false)
+{
+}
+
+void CAX25TX::process()
+{
+  if (m_poLen == 0U)
+    return;
+
+  if (!m_duplex) {
+    if (m_poPtr == 0U) {
+      bool tx = ax25RX.canTX();
+      if (!tx)
+        return;
+    }
+  }
+
+  uint16_t space = io.getSpace();
+
+  while (space > AX25_RADIO_SYMBOL_LENGTH) {
+    bool b = READ_BIT1(m_poBuffer, m_poPtr) != 0U;
+    m_poPtr++;
+
+    writeBit(b);
+
+    space -= AX25_RADIO_SYMBOL_LENGTH;
+
+    if (m_poPtr >= m_poLen) {
+      m_poPtr = 0U;
+      m_poLen = 0U;
+      return;
+    }
+  }
+}
+
+uint8_t CAX25TX::writeData(const uint8_t* data, uint16_t length)
+{
+  CAX25Frame frame(data, length);
+  frame.addCRC();
+
+  m_poLen    = 0U;
+  m_poPtr    = 0U;
+  m_nrzi     = false;
+  m_tablePtr = 0U;
+
+  // Add TX delay
+  for (uint16_t i = 0U; i < m_txDelay; i++, m_poLen++) {
+    bool preamble = NRZI(false);
+    WRITE_BIT1(m_poBuffer, m_poLen, preamble);
+  }
+
+  // Add the Start Flag
+  for (uint16_t i = 0U; i < 8U; i++, m_poLen++) {
+    bool b1 = READ_BIT1(START_FLAG, i) != 0U;
+    bool b2 = NRZI(b1);
+    WRITE_BIT1(m_poBuffer, m_poLen, b2);
+  }
+
+  uint8_t ones = 0U;
+  for (uint16_t i = 0U; i < (frame.m_length * 8U); i++) {
+    bool b1 = READ_BIT2(frame.m_data, i) != 0U;
+    bool b2 = NRZI(b1);
+    WRITE_BIT1(m_poBuffer, m_poLen, b2);
+    m_poLen++;
+
+    if (b1) {
+      ones++;
+      if (ones == AX25_MAX_ONES) {
+        // Bit stuffing
+        bool b = NRZI(false);
+        WRITE_BIT1(m_poBuffer, m_poLen, b);
+        m_poLen++;
+        ones = 0U;
+      }
+    } else {
+      ones = 0U;
+    }
+  }
+
+  // Add the End Flag
+  for (uint16_t i = 0U; i < 8U; i++, m_poLen++) {
+    bool b1 = READ_BIT1(END_FLAG, i) != 0U;
+    bool b2 = NRZI(b1);
+    WRITE_BIT1(m_poBuffer, m_poLen, b2);
+  }
+
+  return 0U;
+}
+
+void CAX25TX::writeBit(bool b)
+{
+  q15_t buffer[AX25_RADIO_SYMBOL_LENGTH];
+  for (uint8_t i = 0U; i < AX25_RADIO_SYMBOL_LENGTH; i++) {
+    q15_t value = AUDIO_TABLE_DATA[m_tablePtr];
+
+    if (b) {
+      // De-emphasise the lower frequency by 6dB
+      value >>= 2;
+      m_tablePtr += 6U;
+    } else {
+      m_tablePtr += 11U;
+    }
+
+    buffer[i] = value;
+
+    if (m_tablePtr >= AUDIO_TABLE_LEN)
+      m_tablePtr -= AUDIO_TABLE_LEN;
+  }
+
+  io.write(STATE_AX25, buffer, AX25_RADIO_SYMBOL_LENGTH);
+}
+
+void CAX25TX::setTXDelay(uint8_t delay)
+{
+  m_txDelay = delay * 12U;
+}
+
+uint8_t CAX25TX::getSpace() const
+{
+  return m_poLen == 0U ? 255U : 0U;
+}
+
+bool CAX25TX::NRZI(bool b)
+{
+    if (!b)
+      m_nrzi = !m_nrzi;
+
+    return m_nrzi;
+}
+
+#endif
+

AX25TX.h

@@ -0,0 +1,53 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_AX25)
+
+#if !defined(AX25TX_H)
+#define  AX25TX_H
+
+class CAX25TX {
+public:
+  CAX25TX();
+
+  uint8_t writeData(const uint8_t* data, uint16_t length);
+
+  void process();
+
+  void setTXDelay(uint8_t delay);
+
+  uint8_t getSpace() const;
+
+private:
+  uint8_t    m_poBuffer[600U];
+  uint16_t   m_poLen;
+  uint16_t   m_poPtr;
+  uint16_t   m_txDelay;
+  uint16_t   m_tablePtr;
+  bool       m_nrzi;
+
+  void writeBit(bool b);
+  bool NRZI(bool b);
+};
+
+#endif
+
+#endif
+

AX25Twist.cpp

@@ -0,0 +1,316 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_AX25)
+
+#include "Globals.h"
+#include "AX25Twist.h"
+
+// 1200Hz = -12dB, 2200Hz = 0dB; 3381Hz cutoff; cosine.
+q15_t dB12[] = {
+  176,
+  -812,
+  -3916,
+  -7586,
+  23536,
+  -7586,
+  -3916,
+  -812,
+  176
+};
+
+// 1200Hz = -11dB, 2200Hz = 0dB; 3258Hz cutoff; cosine.
+q15_t dB11[] = {
+  121,
+  -957,
+  -3959,
+  -7383,
+  23871,
+  -7383,
+  -3959,
+  -957,
+  121
+};
+
+// 1200Hz = -10dB, 2200Hz = 0dB; 3118Hz cutoff; cosine.
+q15_t dB10[] = {
+  56,
+  -1110,
+  -3987,
+  -7141,
+  24254,
+  -7141,
+  -3987,
+  -1110,
+  56
+};
+
+// 1200Hz = -9dB, 2200Hz = 0dB; 2959Hz cutoff; cosine.
+q15_t dB9[] = {
+  -19,
+  -1268,
+  -3994,
+  -6856,
+  24688,
+  -6856,
+  -3994,
+  -1268,
+  -19
+};
+
+// 1200Hz = -8dB, 2200Hz = 0dB; 2778Hz cutoff; cosine.
+q15_t dB8[] = {
+  -104,
+  -1424,
+  -3968,
+  -6516,
+  25182,
+  -6516,
+  -3968,
+  -1424,
+  -104
+};
+
+// 1200Hz = -7dB, 2200Hz = 0dB; 2573Hz cutoff; cosine.
+q15_t dB7[] = {
+  -196,
+  -1565,
+  -3896,
+  -6114,
+  25742,
+  -6114,
+  -3896,
+  -1565,
+  -196
+};
+
+// 1200Hz = -6dB, 2200Hz = 0dB; 2343Hz cutoff; cosine.
+q15_t dB6[] = {
+  -288,
+  -1676,
+  -3761,
+  -5642,
+  26370,
+  -5642,
+  -3761,
+  -1676,
+  -288
+};
+
+// 1200Hz = -5dB, 2200Hz = 0dB; 2085Hz cutoff; cosine.
+q15_t dB5[] = {
+  -370,
+  -1735,
+  -3545,
+  -5088,
+  27075,
+  -5088,
+  -3545,
+  -1735,
+  -370
+};
+
+// 1200Hz = -4dB, 2200Hz = 0dB; 1790Hz cutoff; cosine.
+q15_t dB4[] = {
+  -432,
+  -1715,
+  -3220,
+  -4427,
+  27880,
+  -4427,
+  -3220,
+  -1715,
+  -432
+};
+
+// 1200Hz = -3dB, 2200Hz = 0dB; 1456Hz cutoff; cosine.
+q15_t dB3[] = {
+  -452,
+  -1582,
+  -2759,
+  -3646,
+  28792,
+  -3646,
+  -2759,
+  -1582,
+  -452
+};
+
+// 1200Hz = -2dB, 2200Hz = 0dB; 1070Hz cutoff; cosine.
+q15_t dB2[] = {
+  -408,
+  -1295,
+  -2123,
+  -2710,
+  29846,
+  -2710,
+  -2123,
+  -1295,
+  -408
+};
+
+// 1200Hz = -1dB, 2200Hz = 0dB; 605Hz cutoff; cosine.
+q15_t dB1[] = {
+  -268,
+  -795,
+  -1244,
+  -1546,
+  31116,
+  -1546,
+  -1244,
+  -795,
+  -268
+};
+
+q15_t dB0[] = {
+  0,
+  0,
+  0,
+  0,
+  32767,
+  0,
+  0,
+  0,
+  0,
+};
+
+// 1200Hz = 0dB, 2200Hz = -1dB; 4130Hz cutoff; cosine.
+q15_t dB_1[] = {
+  -419,
+  -177,
+  3316,
+  8650,
+  11278,
+  8650,
+  3316,
+  -177,
+  -419
+};
+
+// 1200Hz = 0dB, 2200Hz = -2dB; 3190Hz cutoff; cosine.
+q15_t dB_2[] = {
+  -90,
+  1033,
+  3975,
+  7267,
+  8711,
+  7267,
+  3975,
+  1033,
+  -90
+};
+
+// 1200Hz = 0dB, 2200Hz = -3dB; 2330Hz cutoff; cosine.
+q15_t dB_3[] = {
+  292,
+  1680,
+  3752,
+  5615,
+  6362,
+  5615,
+  3752,
+  1680,
+  292
+};
+
+// 1200Hz = 0dB, 2200Hz = -4dB; 2657Hz cutoff; boxcar.
+q15_t dB_4[] = {
+  917,
+  3024,
+  5131,
+  6684,
+  7255,
+  6684,
+  5131,
+  3024,
+  917
+};
+
+// 1200Hz = 0dB, 2200Hz = -5dB; 2360Hz cutoff; boxcar.
+q15_t dB_5[] = {
+  1620,
+  3339,
+  4925,
+  6042,
+  6444,
+  6042,
+  4925,
+  3339,
+  1620
+};
+
+// 1200Hz = 0dB, 2200Hz = -6dB; 2067Hz cutoff; boxcar.
+q15_t dB_6[] = {
+  2161,
+  3472,
+  4605,
+  5373,
+  5644,
+  5373,
+  4605,
+  3472,
+  2161
+};
+
+q15_t* coeffs[] = {
+  dB12,
+  dB11,
+  dB10,
+  dB9,
+  dB8,
+  dB7,
+  dB6,
+  dB5,
+  dB4,
+  dB3,
+  dB2,
+  dB1,
+  dB0,
+  dB_1,
+  dB_2,
+  dB_3,
+  dB_4,
+  dB_5,
+  dB_6
+};
+
+CAX25Twist::CAX25Twist(int8_t n) :
+m_filter(),
+m_state()
+{
+  setTwist(n);
+}
+
+void CAX25Twist::process(q15_t* in, q15_t* out, uint8_t length)
+{
+  ::arm_fir_fast_q15(&m_filter, in, out, length);
+}
+
+void CAX25Twist::setTwist(int8_t n)
+{
+  uint8_t twist = uint8_t(n + 6);
+
+  m_filter.numTaps = 9;
+  m_filter.pState  = m_state;
+  m_filter.pCoeffs = coeffs[twist];
+}
+
+#endif
+

AX25Twist.h

@@ -0,0 +1,42 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_AX25)
+
+#if !defined(AX25Twist_H)
+#define  AX25Twist_H
+
+class CAX25Twist {
+public:
+  CAX25Twist(int8_t n);
+
+  void process(q15_t* in, q15_t* out, uint8_t length);
+
+  void setTwist(int8_t n);
+
+private:
+  arm_fir_instance_q15 m_filter;
+  q15_t                m_state[40U];   // NoTaps + BlockSize - 1, 9 + 20 - 1 plus some spare
+};
+
+#endif
+
+#endif
+

CWIdTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -125,7 +125,7 @@ void CCWIdTX::process()
   }
 }
 
-uint8_t CCWIdTX::write(const uint8_t* data, uint8_t length)
+uint8_t CCWIdTX::write(const uint8_t* data, uint16_t length)
 {
   ::memset(m_poBuffer, 0x00U, 1000U * sizeof(uint8_t));
 

CWIdTX.h

@@ -1,6 +1,6 @@
 /*
  *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
- *   Copyright (C) 2016 by Colin Durbridge G4EML
+ *   Copyright (C) 2016,2020 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -28,7 +28,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
   void reset();
 

CalDMR.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -18,6 +18,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DMR)
+
 #include "Globals.h"
 #include "CalDMR.h"
 
@@ -208,7 +211,7 @@ void CCalDMR::dmrdmo1k()
   }
 }
 
-uint8_t CCalDMR::write(const uint8_t* data, uint8_t length)
+uint8_t CCalDMR::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
@@ -221,3 +224,5 @@ uint8_t CCalDMR::write(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
+#endif
+

CalDMR.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -17,10 +17,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DMR)
+
 #if !defined(CALDMR_H)
 #define  CALDMR_H
 
-#include "Config.h"
 #include "DMRDefines.h"
 
 enum DMRCAL1K {
@@ -41,7 +44,7 @@ public:
   void createData1k(uint8_t n);
   void createDataDMO1k(uint8_t n);
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   bool      m_transmit;
@@ -53,3 +56,5 @@ private:
 
 #endif
 
+#endif
+

CalDStarRX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2016,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DSTAR)
+
 #include "Globals.h"
 #include "CalDStarRX.h"
 #include "Utils.h"
@@ -24,7 +27,7 @@
 const unsigned int BUFFER_LENGTH = 200U;
 
 const uint32_t PLLMAX = 0x10000U;
-const uint32_t PLLINC = PLLMAX / DSTAR_RADIO_BIT_LENGTH;
+const uint32_t PLLINC = PLLMAX / DSTAR_RADIO_SYMBOL_LENGTH;
 const uint32_t INC    = PLLINC / 32U;
 
 // D-Star bit order version of 0x55 0x2D 0x16
@@ -126,3 +129,5 @@ void CCalDStarRX::process(q15_t value)
   }
 }
 
+#endif
+

CalDStarRX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,10 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DSTAR)
+
 #if !defined(CALDSTARRX_H)
 #define  CALDSTARRX_H
 
-#include "Config.h"
 #include "DStarDefines.h"
 
 class CCalDStarRX {
@@ -40,3 +43,5 @@ private:
 
 #endif
 
+#endif
+

CalDStarTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2016,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DSTAR)
+
 #include "Globals.h"
 #include "CalDStarTX.h"
 
@@ -162,7 +165,7 @@ void CCalDStarTX::process()
   m_count = (m_count + 1U) % (30U * 21U);
 }
 
-uint8_t CCalDStarTX::write(const uint8_t* data, uint8_t length)
+uint8_t CCalDStarTX::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
@@ -181,3 +184,5 @@ uint8_t CCalDStarTX::write(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
+#endif
+

CalDStarTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,17 +16,20 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DSTAR)
+
 #if !defined(CALDSTARTX_H)
 #define  CALDSTARTX_H
 
-#include "Config.h"
 #include "DStarDefines.h"
 
 class CCalDStarTX {
 public:
   CCalDStarTX();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
   void process();
 
@@ -37,3 +40,5 @@ private:
 
 #endif
 
+#endif
+

CalFM.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2020 by Phil Taylor M0VSE
  *
@@ -19,6 +19,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_FM)
+
 #include "Globals.h"
 #include "CalFM.h"
 
@@ -52,7 +55,7 @@ void CCalFM::process()
 {
   const TONE_TABLE* entry = NULL;
 
-  if (m_modemState!=m_lastState)
+  if (m_modemState != m_lastState)
   {
     switch (m_modemState) {
         case STATE_FMCAL10K:
@@ -116,7 +119,7 @@ void CCalFM::process()
 }
 
 
-uint8_t CCalFM::write(const uint8_t* data, uint8_t length)
+uint8_t CCalFM::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
@@ -125,3 +128,6 @@ uint8_t CCalFM::write(const uint8_t* data, uint8_t length)
 
   return 0U;
 }
+
+#endif
+

CalFM.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2020 by Phil Taylor M0VSE
  *
@@ -18,11 +18,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_FM)
+
 #if !defined(CALFM_H)
 #define  CALFM_H
 
-#include "Config.h"
-
 class CCalFM {
 public:
   CCalFM();
@@ -35,7 +37,7 @@ public:
   void fm25kcal();
   void fm30kcal();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   uint16_t  m_frequency;
@@ -49,3 +51,5 @@ private:
 
 #endif
 
+#endif
+

CalNXDN.cpp

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +18,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_NXDN)
+
 #include "Globals.h"
 #include "CalNXDN.h"
 
@@ -79,7 +83,7 @@ void CCalNXDN::process()
   }
 }
 
-uint8_t CCalNXDN::write(const uint8_t* data, uint8_t length)
+uint8_t CCalNXDN::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
@@ -92,3 +96,5 @@ uint8_t CCalNXDN::write(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
+#endif
+

CalNXDN.h

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,11 +17,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_NXDN)
+
 #if !defined(CALNXDN_H)
 #define  CALNXDN_H
 
-#include "Config.h"
-
 enum NXDNCAL1K {
   NXDNCAL1K_IDLE,
   NXDNCAL1K_TX
@@ -32,7 +35,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   bool      m_transmit;
@@ -42,3 +45,5 @@ private:
 
 #endif
 
+#endif
+

CalP25.cpp

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +18,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_P25)
+
 #include "Globals.h"
 #include "CalP25.h"
 
@@ -82,7 +86,7 @@ void CCalP25::process()
   }
 }
 
-uint8_t CCalP25::write(const uint8_t* data, uint8_t length)
+uint8_t CCalP25::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
@@ -95,3 +99,5 @@ uint8_t CCalP25::write(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
+#endif
+

CalP25.h

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,10 +17,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_P25)
+
 #if !defined(CALP25_H)
 #define  CALP25_H
 
-#include "Config.h"
 #include "P25Defines.h"
 
 enum P25CAL1K {
@@ -34,7 +38,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   bool      m_transmit;
@@ -43,3 +47,5 @@ private:
 
 #endif
 
+#endif
+

CalPOCSAG.cpp

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2019 by Florian Wolters DF2ET
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,10 +18,12 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_POCSAG)
+
 #include "Globals.h"
 #include "CalPOCSAG.h"
 
-
 CCalPOCSAG::CCalPOCSAG() :
 m_state(POCSAGCAL_IDLE)
 {
@@ -38,7 +41,7 @@ void CCalPOCSAG::process()
   pocsagTX.writeByte(0xAAU);
 }
 
-uint8_t CCalPOCSAG::write(const uint8_t* data, uint8_t length)
+uint8_t CCalPOCSAG::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
@@ -47,3 +50,6 @@ uint8_t CCalPOCSAG::write(const uint8_t* data, uint8_t length)
 
   return 0U;
 }
+
+#endif
+

CalPOCSAG.h

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2019 by Florian Wolters DF2ET
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,11 +17,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_POCSAG)
+
 #if !defined(CALPOCSAG_H)
 #define  CALPOCSAG_H
 
-#include "Config.h"
-
 enum POCSAGCAL {
   POCSAGCAL_IDLE,
   POCSAGCAL_TX
@@ -32,10 +35,13 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   POCSAGCAL m_state;
 };
 
 #endif
+
+#endif
+

Config.h

@@ -19,6 +19,37 @@
 #if !defined(CONFIG_H)
 #define  CONFIG_H
 
+// Allow for the selection of which modes to compile into the firmware. This is particularly useful for processors
+// which have limited code space and processing power like the STM32F103, which is found on older/cheaper boards.
+
+// Enable D-Star support.
+#define MODE_DSTAR
+
+// Enable DMR support.
+#define MODE_DMR
+
+// Enable System Fusion support.
+#define MODE_YSF
+
+// Enable P25 phase 1 support.
+#define MODE_P25
+
+// Enable NXDN support, the boxcar filter sometimes improves the performance of NXDN receive on some systems.
+#define MODE_NXDN
+#define USE_NXDN_BOXCAR
+
+// Enable M17 support.
+#define MODE_M17
+
+// Enable POCSAG support.
+#define MODE_POCSAG
+
+// Enable FM support.
+#define MODE_FM
+
+// Enable AX.25 support, this is only enabled if FM is also enabled.
+#define MODE_AX25
+
 // Allow for the use of high quality external clock oscillators
 // The number is the frequency of the oscillator in Hertz.
 //
@@ -35,11 +66,16 @@
 // For 19.2 MHz
 // #define EXTERNAL_OSC 19200000
 
+// Select a baud rate for host communication. The faster speeds are needed for external FM to work.
+// #define SERIAL_SPEED 115200 // Suitable for most older boards (Arduino Due, STM32F1_POG, etc). External FM will NOT work with this!
+// #define SERIAL_SPEED 230400 // Only works on newer boards like fast M4, M7, Teensy 3.x. External FM might work with this
+#define SERIAL_SPEED 460800	// Only works on newer boards like fast M4, M7, Teensy 3.x. External FM should work with this
+
 // Allow the use of the COS line to lockout the modem
 // #define USE_COS_AS_LOCKOUT
 
 // Use pins to output the current mode via LEDs
-// #define MODE_LEDS
+#define MODE_LEDS
 
 // For the original Arduino Due pin layout
 // #define ARDUINO_DUE_PAPA
@@ -49,7 +85,7 @@
 #define STM32F1_POG
 #else
 // For the ZUM V1.0 and V1.0.1 boards pin layout
-#define ARDUINO_DUE_ZUM_V10
+// #define ARDUINO_DUE_ZUM_V10
 #endif
 
 // For the SP8NTH board
@@ -66,10 +102,13 @@
 // #define VK6MST_TEENSY_PI3_SHIELD_I2C
 
 // Pass RSSI information to the host
-// #define SEND_RSSI_DATA
+#define SEND_RSSI_DATA
 
 // Use the modem as a serial repeater for Nextion displays
-// #define SERIAL_REPEATER
+#define SERIAL_REPEATER
+
+// Use the modem as an I2C repeater for OLED displays
+// #define I2C_REPEATER
 
 // To reduce CPU load, you can remove the DC blocker by commenting out the next line
 #define USE_DCBLOCKER
@@ -81,10 +120,20 @@
 // Use the YSF and P25 LEDs for NXDN
 // #define USE_ALTERNATE_NXDN_LEDS
 
+// Use the D-Star and P25 LEDs for M17
+#define USE_ALTERNATE_M17_LEDS
+
 // Use the D-Star and DMR LEDs for POCSAG
-// #define USE_ALTERNATE_POCSAG_LEDS
+#define USE_ALTERNATE_POCSAG_LEDS
 
 // Use the D-Star and YSF LEDs for FM
 #define USE_ALTERNATE_FM_LEDS
 
+#if defined(STM32F1_POG)
+// Slower boards need to run their serial at 115200 baud
+#undef SERIAL_SPEED
+#define SERIAL_SPEED 115200
 #endif
+
+#endif
+

DMRDMORX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DMR)
+
 #include "Globals.h"
 #include "DMRDMORX.h"
 #include "DMRSlotType.h"
@@ -423,3 +426,6 @@ void CDMRDMORX::writeRSSIData(uint8_t* frame)
   serial.writeDMRData(true, frame, DMR_FRAME_LENGTH_BYTES + 1U);
 #endif
 }
+
+#endif
+

DMRDMORX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,10 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DMR)
+
 #if !defined(DMRDMORX_H)
 #define  DMRDMORX_H
 
-#include "Config.h"
 #include "DMRDefines.h"
 
 const uint16_t DMO_BUFFER_LENGTH_SAMPLES = 1440U;   // 60ms at 24 kHz
@@ -67,3 +70,6 @@ private:
 };
 
 #endif
+
+#endif
+

DMRDMOTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
@@ -19,6 +19,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DMR)
+
 #include "Globals.h"
 #include "DMRSlotType.h"
 
@@ -74,7 +77,7 @@ void CDMRDMOTX::process()
       m_poLen = m_txDelay;
     } else {
       for (unsigned int i = 0U; i < DMR_FRAME_LENGTH_BYTES; i++)
-        m_poBuffer[i] = m_fifo.get();
+        m_fifo.get(m_poBuffer[i]);
 
       for (unsigned int i = 0U; i < 39U; i++)
         m_poBuffer[i + DMR_FRAME_LENGTH_BYTES] = PR_FILL[i];
@@ -104,7 +107,7 @@ void CDMRDMOTX::process()
   }
 }
 
-uint8_t CDMRDMOTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CDMRDMOTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != (DMR_FRAME_LENGTH_BYTES + 1U))
     return 4U;
@@ -161,3 +164,5 @@ void CDMRDMOTX::setTXDelay(uint8_t delay)
     m_txDelay = 1200U;
 }
 
+#endif
+

DMRDMOTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -17,19 +17,22 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DMR)
+
 #if !defined(DMRDMOTX_H)
 #define  DMRDMOTX_H
 
-#include "Config.h"
 #include "DMRDefines.h"
 
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CDMRDMOTX {
 public:
   CDMRDMOTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();
 
@@ -38,7 +41,7 @@ public:
   uint8_t getSpace() const;
 
 private:
-  CSerialRB                        m_fifo;
+  CRingBuffer<uint8_t>                        m_fifo;
   arm_fir_interpolate_instance_q15 m_modFilter;
   q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare
   uint8_t                          m_poBuffer[1200U];
@@ -51,3 +54,5 @@ private:
 
 #endif
 
+#endif
+

DMRIdleRX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DMR)
+
 #include "Globals.h"
 #include "DMRIdleRX.h"
 #include "DMRSlotType.h"
@@ -209,3 +212,6 @@ void CDMRIdleRX::setColorCode(uint8_t colorCode)
 {
   m_colorCode = colorCode;
 }
+
+#endif
+

DMRIdleRX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,10 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DMR)
+
 #if !defined(DMRIDLERX_H)
 #define  DMRIDLERX_H
 
-#include "Config.h"
 #include "DMRDefines.h"
 
 class CDMRIdleRX {
@@ -49,3 +52,5 @@ private:
 
 #endif
 
+#endif
+

DMRRX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DMR)
+
 #include "Globals.h"
 #include "DMRRX.h"
 
@@ -68,3 +71,5 @@ void CDMRRX::reset()
   m_slot2RX.reset();
 }
 
+#endif
+

DMRRX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,10 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DMR)
+
 #if !defined(DMRRX_H)
 #define  DMRRX_H
 
-#include "Config.h"
 #include "DMRSlotRX.h"
 
 class CDMRRX {
@@ -40,3 +43,5 @@ private:
 
 #endif
 
+#endif
+

DMRSlotRX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DMR)
+
 #include "Globals.h"
 #include "DMRSlotRX.h"
 #include "DMRSlotType.h"
@@ -400,3 +403,6 @@ void CDMRSlotRX::writeRSSIData(uint8_t* frame)
   serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
 #endif
 }
+
+#endif
+

DMRSlotRX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,10 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DMR)
+
 #if !defined(DMRSLOTRX_H)
 #define  DMRSLOTRX_H
 
-#include "Config.h"
 #include "DMRDefines.h"
 
 enum DMRRX_STATE {
@@ -70,3 +73,6 @@ private:
 };
 
 #endif
+
+#endif
+

DMRSlotType.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DMR)
+
 #include "Globals.h"
 #include "DMRSlotType.h"
 
@@ -285,3 +288,5 @@ void CDMRSlotType::encode(uint8_t colorCode, uint8_t dataType, uint8_t* frame) c
   frame[20U] = (frame[20U] & 0x03U) | ((slotType[1U] << 6) & 0xC0U) | ((slotType[2U] >> 2) & 0x3CU);
 }
 
+#endif
+

DMRSlotType.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,6 +16,10 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DMR)
+
 #if !defined(DMRSLOTTYPE_H)
 #define  DMRSLOTTYPE_H
 
@@ -35,3 +39,5 @@ private:
 
 #endif
 
+#endif
+

DMRTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
@@ -19,6 +19,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DMR)
+
 #include "Globals.h"
 #include "DMRSlotType.h"
 
@@ -144,7 +147,7 @@ void CDMRTX::process()
   }
 }
 
-uint8_t CDMRTX::writeData1(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeData1(const uint8_t* data, uint16_t length)
 {
   if (length != (DMR_FRAME_LENGTH_BYTES + 1U))
     return 4U;
@@ -168,7 +171,7 @@ uint8_t CDMRTX::writeData1(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
-uint8_t CDMRTX::writeData2(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeData2(const uint8_t* data, uint16_t length)
 {
   if (length != (DMR_FRAME_LENGTH_BYTES + 1U))
     return 4U;
@@ -192,7 +195,7 @@ uint8_t CDMRTX::writeData2(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
-uint8_t CDMRTX::writeShortLC(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeShortLC(const uint8_t* data, uint16_t length)
 {
   if (length != 9U)
     return 4U;
@@ -208,7 +211,7 @@ uint8_t CDMRTX::writeShortLC(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
-uint8_t CDMRTX::writeAbort(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeAbort(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
@@ -293,7 +296,7 @@ void CDMRTX::createData(uint8_t slotIndex)
 {
   if (m_fifo[slotIndex].getData() >= DMR_FRAME_LENGTH_BYTES && m_frameCount >= STARTUP_COUNT && m_abortCount[slotIndex] >= ABORT_COUNT) {
     for (unsigned int i = 0U; i < DMR_FRAME_LENGTH_BYTES; i++) {
-      m_poBuffer[i]   = m_fifo[slotIndex].get();
+      m_fifo[slotIndex].get(m_poBuffer[i]);
       m_markBuffer[i] = MARK_NONE;
     }
   } else {
@@ -414,3 +417,6 @@ uint32_t CDMRTX::getFrameCount()
 {
   return m_frameCount;
 }
+
+#endif
+

DMRTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -17,13 +17,16 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DMR)
+
 #if !defined(DMRTX_H)
 #define  DMRTX_H
 
-#include "Config.h"
 #include "DMRDefines.h"
 
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 enum DMRTXSTATE {
   DMRTXSTATE_IDLE,
@@ -38,11 +41,11 @@ class CDMRTX {
 public:
   CDMRTX();
 
-  uint8_t writeData1(const uint8_t* data, uint8_t length);
-  uint8_t writeData2(const uint8_t* data, uint8_t length);
+  uint8_t writeData1(const uint8_t* data, uint16_t length);
+  uint8_t writeData2(const uint8_t* data, uint16_t length);
 
-  uint8_t writeShortLC(const uint8_t* data, uint8_t length);
-  uint8_t writeAbort(const uint8_t* data, uint8_t length);
+  uint8_t writeShortLC(const uint8_t* data, uint16_t length);
+  uint8_t writeAbort(const uint8_t* data, uint16_t length);
 
   void setStart(bool start);
   void setCal(bool start);
@@ -59,7 +62,7 @@ public:
   void setColorCode(uint8_t colorCode);
 
 private:
-  CSerialRB                        m_fifo[2U];
+  CRingBuffer<uint8_t>                        m_fifo[2U];
   arm_fir_interpolate_instance_q15 m_modFilter;
   q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare
   DMRTXSTATE                       m_state;
@@ -83,3 +86,5 @@ private:
 
 #endif
 
+#endif
+

DStarDefines.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -19,30 +19,50 @@
 #if !defined(DSTARDEFINES_H)
 #define  DSTARDEFINES_H
 
-const unsigned int DSTAR_RADIO_BIT_LENGTH = 5U;      // At 24 kHz sample rate
+const unsigned int DSTAR_RADIO_SYMBOL_LENGTH = 5U;      // At 24 kHz sample rate
 
-const unsigned int DSTAR_HEADER_LENGTH_BYTES = 41U;
-const unsigned int DSTAR_HEADER_LENGTH_BITS  = DSTAR_HEADER_LENGTH_BYTES * 8U;
+const unsigned int DSTAR_HEADER_LENGTH_BYTES   = 41U;
 
-const unsigned int DSTAR_FEC_SECTION_LENGTH_BYTES = 83U;
-const unsigned int DSTAR_FEC_SECTION_LENGTH_BITS  = 660U;
+const unsigned int DSTAR_FEC_SECTION_LENGTH_BYTES   = 83U;
+const unsigned int DSTAR_FEC_SECTION_LENGTH_SYMBOLS = 660U;
+const unsigned int DSTAR_FEC_SECTION_LENGTH_SAMPLES = DSTAR_FEC_SECTION_LENGTH_SYMBOLS * DSTAR_RADIO_SYMBOL_LENGTH;
 
-const unsigned int DSTAR_DATA_LENGTH_BYTES = 12U;
-const unsigned int DSTAR_DATA_LENGTH_BITS  = DSTAR_DATA_LENGTH_BYTES * 8U;
+const unsigned int DSTAR_DATA_LENGTH_BYTES   = 12U;
+const unsigned int DSTAR_DATA_LENGTH_SYMBOLS = DSTAR_DATA_LENGTH_BYTES * 8U;
+const unsigned int DSTAR_DATA_LENGTH_SAMPLES = DSTAR_DATA_LENGTH_SYMBOLS * DSTAR_RADIO_SYMBOL_LENGTH;
 
-const uint8_t      DSTAR_EOT_BYTES[] = {0x55, 0x55, 0x55, 0x55, 0xC8, 0x7A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
-const unsigned int DSTAR_EOT_LENGTH_BYTES = 6U;
-const unsigned int DSTAR_EOT_LENGTH_BITS  = DSTAR_EOT_LENGTH_BYTES * 8U;
+const unsigned int DSTAR_END_SYNC_LENGTH_BYTES = 6U;
+const unsigned int DSTAR_END_SYNC_LENGTH_BITS  = DSTAR_END_SYNC_LENGTH_BYTES * 8U;
 
-const uint8_t      DSTAR_DATA_SYNC_LENGTH_BYTES = 3U;
-const uint8_t      DSTAR_DATA_SYNC_LENGTH_BITS  = DSTAR_DATA_SYNC_LENGTH_BYTES * 8U;
+const unsigned int DSTAR_FRAME_SYNC_LENGTH_BYTES   = 3U;
+const unsigned int DSTAR_FRAME_SYNC_LENGTH_SYMBOLS = DSTAR_FRAME_SYNC_LENGTH_BYTES * 8U;
+const unsigned int DSTAR_FRAME_SYNC_LENGTH_SAMPLES = DSTAR_FRAME_SYNC_LENGTH_SYMBOLS * DSTAR_RADIO_SYMBOL_LENGTH;
 
-const uint8_t      DSTAR_DATA_SYNC_BYTES[] = {0x9E, 0x8D, 0x32, 0x88, 0x26, 0x1A, 0x3F, 0x61, 0xE8, 0x55, 0x2D, 0x16};
+const unsigned int DSTAR_DATA_SYNC_LENGTH_BYTES   = 3U;
+const unsigned int DSTAR_DATA_SYNC_LENGTH_SYMBOLS = DSTAR_DATA_SYNC_LENGTH_BYTES * 8U;
+const unsigned int DSTAR_DATA_SYNC_LENGTH_SAMPLES = DSTAR_DATA_SYNC_LENGTH_SYMBOLS * DSTAR_RADIO_SYMBOL_LENGTH;
 
-const uint8_t      DSTAR_SLOW_DATA_TYPE_TEXT   = 0x40U;
-const uint8_t      DSTAR_SLOW_DATA_TYPE_HEADER = 0x50U;
+const uint8_t DSTAR_DATA_SYNC_BYTES[] = {0x9E, 0x8D, 0x32, 0x88, 0x26, 0x1A, 0x3F, 0x61, 0xE8, 0x55, 0x2D, 0x16};
 
-const uint8_t      DSTAR_SCRAMBLER_BYTES[] = {0x70U, 0x4FU, 0x93U};
+// D-Star bit order version of 0x55 0x6E 0x0A
+const uint32_t DSTAR_FRAME_SYNC_DATA = 0x00557650U;
+const uint32_t DSTAR_FRAME_SYNC_MASK = 0x00FFFFFFU;
+const bool     DSTAR_FRAME_SYNC_SYMBOLS[] = {false, true, false, true, false, true, false, true, false, true, true, true, false, true, true, false, false, true, false, true, false, false, false, false};
+
+// D-Star bit order version of 0x55 0x2D 0x16
+const uint32_t DSTAR_DATA_SYNC_DATA = 0x00AAB468U;
+const uint32_t DSTAR_DATA_SYNC_MASK = 0x00FFFFFFU;
+const bool     DSTAR_DATA_SYNC_SYMBOLS[] = {true, false, true, false, true, false, true, false, true, false, true, true, false, true, false, false, false, true, true, false, true, false, false, false};
+
+// D-Star bit order version of 0x55 0x55 0xC8 0x7A
+const uint32_t DSTAR_END_SYNC_DATA = 0xAAAA135EU;
+const uint32_t DSTAR_END_SYNC_MASK = 0xFFFFFFFFU;
+const uint8_t  DSTAR_END_SYNC_BYTES[] = {0x55, 0x55, 0x55, 0x55, 0xC8, 0x7A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+
+const uint8_t  DSTAR_SLOW_DATA_TYPE_TEXT   = 0x40U;
+const uint8_t  DSTAR_SLOW_DATA_TYPE_HEADER = 0x50U;
+
+const uint8_t  DSTAR_SCRAMBLER_BYTES[] = {0x70U, 0x4FU, 0x93U};
 
 #endif
 

DStarRX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -18,31 +18,28 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DSTAR)
+
 #include "Globals.h"
 #include "DStarRX.h"
 #include "Utils.h"
 
-const unsigned int BUFFER_LENGTH = 200U;
-
-const uint32_t PLLMAX = 0x10000U;
-const uint32_t PLLINC = PLLMAX / DSTAR_RADIO_BIT_LENGTH;
-const uint32_t INC    = PLLINC / 32U;
-
-const unsigned int MAX_SYNC_BITS = 100U * DSTAR_DATA_LENGTH_BITS;
+const unsigned int MAX_FRAMES = 150U;
 
 // D-Star bit order version of 0x55 0x55 0x6E 0x0A
-const uint32_t FRAME_SYNC_DATA = 0x00557650U;
-const uint32_t FRAME_SYNC_MASK = 0x00FFFFFFU;
+const uint64_t FRAME_SYNC_DATA = 0x0000000000557650U;
+const uint64_t FRAME_SYNC_MASK = 0x0000000000FFFFFFU;
 const uint8_t  FRAME_SYNC_ERRS = 2U;
 
 // D-Star bit order version of 0x55 0x2D 0x16
-const uint32_t DATA_SYNC_DATA = 0x00AAB468U;
-const uint32_t DATA_SYNC_MASK = 0x00FFFFFFU;
+const uint64_t DATA_SYNC_DATA = 0x0000000000AAB468U;
+const uint64_t DATA_SYNC_MASK = 0x0000000000FFFFFFU;
 const uint8_t  DATA_SYNC_ERRS = 2U;
 
 // D-Star bit order version of 0x55 0x55 0xC8 0x7A
-const uint32_t END_SYNC_DATA = 0xAAAA135EU;
-const uint32_t END_SYNC_MASK = 0xFFFFFFFFU;
+const uint64_t END_SYNC_DATA = 0x0000AAAAAAAA135EU;
+const uint64_t END_SYNC_MASK = 0x0000FFFFFFFFFFFFU;
 const uint8_t  END_SYNC_ERRS = 1U;
 
 const uint8_t BIT_MASK_TABLE0[] = {0x7FU, 0xBFU, 0xDFU, 0xEFU, 0xF7U, 0xFBU, 0xFDU, 0xFEU};
@@ -237,14 +234,24 @@ const uint16_t CCITT_TABLE[] = {
   0xf78fU, 0xe606U, 0xd49dU, 0xc514U, 0xb1abU, 0xa022U, 0x92b9U, 0x8330U,
   0x7bc7U, 0x6a4eU, 0x58d5U, 0x495cU, 0x3de3U, 0x2c6aU, 0x1ef1U, 0x0f78U};
 
+const uint16_t NOENDPTR = 9999U;
+
 CDStarRX::CDStarRX() :
-m_pll(0U),
-m_prev(false),
 m_rxState(DSRXS_NONE),
-m_patternBuffer(0x00U),
-m_rxBuffer(),
-m_rxBufferBits(0U),
-m_dataBits(0U),
+m_bitBuffer(),
+m_headerBuffer(),
+m_dataBuffer(),
+m_bitPtr(0U),
+m_headerPtr(0U),
+m_dataPtr(0U),
+m_startPtr(NOENDPTR),
+m_syncPtr(NOENDPTR),
+m_minSyncPtr(NOENDPTR),
+m_maxSyncPtr(NOENDPTR),
+m_maxFrameCorr(0),
+m_maxDataCorr(0),
+m_frameCount(0U),
+m_countdown(0U),
 m_mar(0U),
 m_pathMetric(),
 m_pathMemory0(),
@@ -259,14 +266,20 @@ m_rssiCount(0U)
 
 void CDStarRX::reset()
 {
-  m_pll           = 0U;
-  m_prev          = false;
-  m_rxState       = DSRXS_NONE;
-  m_patternBuffer = 0x00U;
-  m_rxBufferBits  = 0U;
-  m_dataBits      = 0U;
-  m_rssiAccum     = 0U;
-  m_rssiCount     = 0U;
+  m_rxState      = DSRXS_NONE;
+  m_headerPtr    = 0U;
+  m_dataPtr      = 0U;
+  m_bitPtr       = 0U;
+  m_maxFrameCorr = 0;
+  m_maxDataCorr  = 0;
+  m_startPtr     = NOENDPTR;
+  m_syncPtr      = NOENDPTR;
+  m_minSyncPtr   = NOENDPTR;
+  m_maxSyncPtr   = NOENDPTR;
+  m_frameCount   = 0U;
+  m_countdown    = 0U;
+  m_rssiAccum    = 0U;
+  m_rssiCount    = 0U;
 }
 
 void CDStarRX::samples(const q15_t* samples, const uint16_t* rssi, uint8_t length)
@@ -275,125 +288,117 @@ void CDStarRX::samples(const q15_t* samples, const uint16_t* rssi, uint8_t lengt
     m_rssiAccum += rssi[i];
     m_rssiCount++;
 
-    bool bit = samples[i] < 0;
+    q15_t sample = samples[i];
 
-    if (bit != m_prev) {
-      if (m_pll < (PLLMAX / 2U))
-        m_pll += INC;
-      else
-        m_pll -= INC;
+    m_bitBuffer[m_bitPtr] <<= 1;
+    if (sample < 0)
+      m_bitBuffer[m_bitPtr] |= 0x01U;
+
+    m_dataBuffer[m_dataPtr] = sample;
+
+    switch (m_rxState) {
+      case DSRXS_HEADER:
+        processHeader(sample);
+        break;
+      case DSRXS_DATA:
+        processData();
+        break;
+      default:
+        processNone(sample);
+        break;
     }
 
-    m_prev = bit;
+    m_dataPtr++;
+    if (m_dataPtr >= DSTAR_DATA_LENGTH_SAMPLES)
+      m_dataPtr = 0U;
 
-    m_pll += PLLINC;
-
-    if (m_pll >= PLLMAX) {
-      m_pll -= PLLMAX;
-
-      switch (m_rxState) {
-        case DSRXS_NONE:
-          processNone(bit);
-          break;
-        case DSRXS_HEADER:
-          processHeader(bit);
-          break;
-        case DSRXS_DATA:
-          processData(bit);
-          break;
-        default:
-          break;
-      }
-    }
+    m_bitPtr++;
+    if (m_bitPtr >= DSTAR_RADIO_SYMBOL_LENGTH)
+      m_bitPtr = 0U;
   }
 }
 
-void CDStarRX::processNone(bool bit)
+void CDStarRX::processNone(q15_t sample)
 {
-  m_patternBuffer <<= 1;
-  if (bit)
-    m_patternBuffer |= 0x01U;
-
   // Fuzzy matching of the frame sync sequence
-  if (countBits32((m_patternBuffer & FRAME_SYNC_MASK) ^ FRAME_SYNC_DATA) <= FRAME_SYNC_ERRS) {
-    DEBUG1("DStarRX: found frame sync in None");
+  bool ret = correlateFrameSync();
+  if (ret) {
+    m_countdown = 5U;
 
-    ::memset(m_rxBuffer, 0x00U, DSTAR_FEC_SECTION_LENGTH_BYTES);
-    m_rxBufferBits = 0U;
+    m_headerBuffer[m_headerPtr] = sample;
+    m_headerPtr++;
 
     m_rssiAccum = 0U;
     m_rssiCount = 0U;
 
     m_rxState = DSRXS_HEADER;
+
     return;
   }
 
-  // Exact matching of the data sync bit sequence
-  if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) == 0U) {
+  // Fuzzy matching of the data sync bit sequence
+  ret = correlateDataSync();
+  if (ret) {
     DEBUG1("DStarRX: found data sync in None");
 
     io.setDecode(true);
     io.setADCDetection(true);
 
-    // Suppress RSSI on the dummy sync message
-    m_rssiAccum = 0U;
-    m_rssiCount = 0U;
-
-    ::memcpy(m_rxBuffer, DSTAR_DATA_SYNC_BYTES, DSTAR_DATA_LENGTH_BYTES);
-    writeRSSIData(m_rxBuffer);
-
-    ::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES + 2U);
-    m_rxBufferBits = 0U;
-
-    m_dataBits  = MAX_SYNC_BITS;
-    m_rxState   = DSRXS_DATA;
-    return;
+    m_rxState = DSRXS_DATA;
   }
 }
 
-void CDStarRX::processHeader(bool bit)
+void CDStarRX::processHeader(q15_t sample)
 {
-  m_patternBuffer <<= 1;
-  if (bit)
-    m_patternBuffer |= 0x01U;
+  if (m_countdown > 0U) {
+    correlateFrameSync();
+    m_countdown--;
+  }
 
-  WRITE_BIT2(m_rxBuffer, m_rxBufferBits, bit);
-  m_rxBufferBits++;
+  m_headerBuffer[m_headerPtr] = sample;
+  m_headerPtr++;
 
   // A full FEC header
-  if (m_rxBufferBits == DSTAR_FEC_SECTION_LENGTH_BITS) {
-    // Process the scrambling, interleaving and FEC, then return if the chcksum was correct
-    unsigned char header[DSTAR_HEADER_LENGTH_BYTES];
-    bool ok = rxHeader(m_rxBuffer, header);
-    if (ok) {
+  if (m_headerPtr == (DSTAR_FEC_SECTION_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH)) {
+    uint8_t buffer[DSTAR_FEC_SECTION_LENGTH_BYTES];
+    samplesToBits(m_headerBuffer, DSTAR_RADIO_SYMBOL_LENGTH, DSTAR_FEC_SECTION_LENGTH_SYMBOLS, buffer, DSTAR_FEC_SECTION_LENGTH_SAMPLES);
+
+    // Process the scrambling, interleaving and FEC, then return true if the chcksum was correct
+    uint8_t header[DSTAR_HEADER_LENGTH_BYTES];
+    bool ok = rxHeader(buffer, header);
+    if (!ok) {
+      // The checksum failed, return to looking for syncs
+      m_rxState = DSRXS_NONE;
+      m_maxFrameCorr = 0;
+      m_maxDataCorr  = 0;
+    } else {
       io.setDecode(true);
       io.setADCDetection(true);
 
       writeRSSIHeader(header);
-
-      ::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES + 2U);
-      m_rxBufferBits = 0U;
-
-      m_rxState  = DSRXS_DATA;
-      m_dataBits = MAX_SYNC_BITS;
-    } else {
-      // The checksum failed, return to looking for syncs
-      m_rxState = DSRXS_NONE;
     }
   }
+
+  // Ready to start the first data section
+  if (m_headerPtr == (DSTAR_FEC_SECTION_LENGTH_SAMPLES + 2U * DSTAR_RADIO_SYMBOL_LENGTH)) {
+    m_frameCount = 0U;
+    m_dataPtr    = 0U;
+
+    m_startPtr   = 476U;
+    m_syncPtr    = 471U;
+    m_maxSyncPtr = 472U;
+    m_minSyncPtr = 470U;
+
+    DEBUG5("DStarRX: calc start/sync/max/min", m_startPtr, m_syncPtr, m_maxSyncPtr, m_minSyncPtr);
+
+    m_rxState = DSRXS_DATA;
+  }
 }
 
-void CDStarRX::processData(bool bit)
+void CDStarRX::processData()
 {
-  m_patternBuffer <<= 1;
-  if (bit)
-    m_patternBuffer |= 0x01U;
-
-  WRITE_BIT2(m_rxBuffer, m_rxBufferBits, bit);
-  m_rxBufferBits++;
-
   // Fuzzy matching of the end frame sequences
-  if (countBits32((m_patternBuffer & END_SYNC_MASK) ^ END_SYNC_DATA) <= END_SYNC_ERRS) {
+  if (countBits64((m_bitBuffer[m_bitPtr] & DSTAR_END_SYNC_MASK) ^ DSTAR_END_SYNC_DATA) <= END_SYNC_ERRS) {
     DEBUG1("DStarRX: Found end sync in Data");
 
     io.setDecode(false);
@@ -401,35 +406,24 @@ void CDStarRX::processData(bool bit)
 
     serial.writeDStarEOT();
 
+    m_maxFrameCorr = 0;
+    m_maxDataCorr  = 0;
+
     m_rxState = DSRXS_NONE;
     return;
   }
 
   // Fuzzy matching of the data sync bit sequence
-  bool syncSeen = false;
-  if (m_rxBufferBits >= (DSTAR_DATA_LENGTH_BITS - 3U)) {
-    if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) <= DATA_SYNC_ERRS) {
-      m_rxBufferBits = DSTAR_DATA_LENGTH_BITS;
-      m_dataBits     = MAX_SYNC_BITS;
-      syncSeen       = true;
-    }
+  if (m_minSyncPtr < m_maxSyncPtr) {
+    if (m_dataPtr >= m_minSyncPtr && m_dataPtr <= m_maxSyncPtr)
+      correlateDataSync();
+  } else {
+    if (m_dataPtr >= m_minSyncPtr || m_dataPtr <= m_maxSyncPtr)
+      correlateDataSync();
   }
 
-  // Check to see if the sync is arriving late
-  if (m_rxBufferBits == DSTAR_DATA_LENGTH_BITS && !syncSeen) {
-    for (uint8_t i = 1U; i <= 3U; i++) {
-      uint32_t syncMask = DATA_SYNC_MASK >> i;
-      uint32_t syncData = DATA_SYNC_DATA >> i;
-      if (countBits32((m_patternBuffer & syncMask) ^ syncData) <= DATA_SYNC_ERRS) {
-        m_rxBufferBits -= i;
-        break;
-      }
-    }
-  }
-
-  m_dataBits--;
-
-  if (m_dataBits == 0U) {
+  // We've not seen a data sync for too long, signal RXLOST and change to RX_NONE
+  if (m_frameCount >= MAX_FRAMES) {
     DEBUG1("DStarRX: data sync timed out, lost lock");
 
     io.setDecode(false);
@@ -437,24 +431,35 @@ void CDStarRX::processData(bool bit)
 
     serial.writeDStarLost();
 
+    m_maxFrameCorr = 0;
+    m_maxDataCorr  = 0;
+
     m_rxState = DSRXS_NONE;
     return;
   }
 
-  // Send a data frame to the host if the required number of bits have been received, or if a data sync has been seen
-  if (m_rxBufferBits == DSTAR_DATA_LENGTH_BITS) {
-    if (syncSeen) {
-      m_rxBuffer[9U]  = DSTAR_DATA_SYNC_BYTES[9U];
-      m_rxBuffer[10U] = DSTAR_DATA_SYNC_BYTES[10U];
-      m_rxBuffer[11U] = DSTAR_DATA_SYNC_BYTES[11U];
-	    writeRSSIData(m_rxBuffer);
-    } else {
-	    serial.writeDStarData(m_rxBuffer, DSTAR_DATA_LENGTH_BYTES);
-	  }
+  // Send a data frame to the host if the required number of bits have been received
+  if (m_dataPtr == m_maxSyncPtr) {
+    uint8_t buffer[DSTAR_DATA_LENGTH_BYTES + 2U];
+    samplesToBits(m_dataBuffer, m_startPtr, DSTAR_DATA_LENGTH_SYMBOLS, buffer, DSTAR_DATA_LENGTH_SAMPLES);
 
-    // Start the next frame
-    ::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES + 2U);
-    m_rxBufferBits = 0U;
+    if ((m_frameCount % 21U) == 0U) {
+      if (m_frameCount == 0U) {
+        buffer[9U]  = DSTAR_DATA_SYNC_BYTES[9U];
+        buffer[10U] = DSTAR_DATA_SYNC_BYTES[10U];
+        buffer[11U] = DSTAR_DATA_SYNC_BYTES[11U];
+        DEBUG5("DStarRX: found start/sync/max/min", m_startPtr, m_syncPtr, m_maxSyncPtr, m_minSyncPtr);
+      }
+
+      writeRSSIData(buffer);
+    } else {
+      serial.writeDStarData(buffer, DSTAR_DATA_LENGTH_BYTES);
+    }
+
+    m_frameCount++;
+
+    m_maxFrameCorr = 0;
+    m_maxDataCorr  = 0;
   }
 }
 
@@ -500,6 +505,105 @@ void CDStarRX::writeRSSIData(unsigned char* data)
   m_rssiCount = 0U;
 }
 
+bool CDStarRX::correlateFrameSync()
+{
+  if (countBits64((m_bitBuffer[m_bitPtr] & DSTAR_FRAME_SYNC_MASK) ^ DSTAR_FRAME_SYNC_DATA) <= FRAME_SYNC_ERRS) {
+    uint16_t ptr = m_dataPtr + DSTAR_DATA_LENGTH_SAMPLES - DSTAR_FRAME_SYNC_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH;
+    if (ptr >= DSTAR_DATA_LENGTH_SAMPLES)
+      ptr -= DSTAR_DATA_LENGTH_SAMPLES;
+
+    q31_t corr = 0;
+
+    for (uint8_t i = 0U; i < DSTAR_FRAME_SYNC_LENGTH_SYMBOLS; i++) {
+      q15_t val = m_dataBuffer[ptr];
+
+      if (DSTAR_FRAME_SYNC_SYMBOLS[i])
+        corr -= val;
+      else
+        corr += val;
+
+      ptr += DSTAR_RADIO_SYMBOL_LENGTH;
+      if (ptr >= DSTAR_DATA_LENGTH_SAMPLES)
+        ptr -= DSTAR_DATA_LENGTH_SAMPLES;
+    }
+
+    if (corr > m_maxFrameCorr) {
+      m_maxFrameCorr = corr;
+      m_headerPtr    = 0U;
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool CDStarRX::correlateDataSync()
+{
+  uint8_t maxErrs = 0U;
+  if (m_rxState == DSRXS_DATA)
+    maxErrs = DATA_SYNC_ERRS;
+
+  if (countBits64((m_bitBuffer[m_bitPtr] & DSTAR_DATA_SYNC_MASK) ^ DSTAR_DATA_SYNC_DATA) <= maxErrs) {
+    uint16_t ptr = m_dataPtr + DSTAR_DATA_LENGTH_SAMPLES - DSTAR_DATA_SYNC_LENGTH_SAMPLES + DSTAR_RADIO_SYMBOL_LENGTH;
+    if (ptr >= DSTAR_DATA_LENGTH_SAMPLES)
+      ptr -= DSTAR_DATA_LENGTH_SAMPLES;
+
+    q31_t corr = 0;
+
+    for (uint8_t i = 0U; i < DSTAR_DATA_SYNC_LENGTH_SYMBOLS; i++) {
+      q15_t val = m_dataBuffer[ptr];
+
+      if (DSTAR_DATA_SYNC_SYMBOLS[i])
+        corr -= val;
+      else
+        corr += val;
+
+      ptr += DSTAR_RADIO_SYMBOL_LENGTH;
+      if (ptr >= DSTAR_DATA_LENGTH_SAMPLES)
+        ptr -= DSTAR_DATA_LENGTH_SAMPLES;
+    }
+
+    if (corr > m_maxDataCorr) {
+      m_maxDataCorr = corr;
+      m_frameCount  = 0U;
+
+      m_syncPtr    = m_dataPtr;
+
+      m_startPtr   = m_dataPtr + DSTAR_RADIO_SYMBOL_LENGTH;
+      if (m_startPtr >= DSTAR_DATA_LENGTH_SAMPLES)
+        m_startPtr -= DSTAR_DATA_LENGTH_SAMPLES;
+
+      m_maxSyncPtr = m_syncPtr + 1U;
+      if (m_maxSyncPtr >= DSTAR_DATA_LENGTH_SAMPLES)
+        m_maxSyncPtr -= DSTAR_DATA_LENGTH_SAMPLES;
+
+      m_minSyncPtr = m_syncPtr + DSTAR_DATA_LENGTH_SAMPLES - 1U;
+      if (m_minSyncPtr >= DSTAR_DATA_LENGTH_SAMPLES)
+        m_minSyncPtr -= DSTAR_DATA_LENGTH_SAMPLES;
+
+      return true;
+    }
+  }
+
+  return false;
+}
+
+void CDStarRX::samplesToBits(const q15_t* inBuffer, uint16_t start, uint16_t count, uint8_t* outBuffer, uint16_t limit)
+{
+  for (uint16_t i = 0U; i < count; i++) {
+    q15_t sample = inBuffer[start];
+
+    if (sample < 0)
+      WRITE_BIT2(outBuffer, i, true);
+    else
+      WRITE_BIT2(outBuffer, i, false);
+
+    start += DSTAR_RADIO_SYMBOL_LENGTH;
+    if (start >= limit)
+      start -= limit;
+  }
+}
+
 bool CDStarRX::rxHeader(uint8_t* in, uint8_t* out)
 {
   int i;
@@ -715,3 +819,6 @@ bool CDStarRX::checksum(const uint8_t* header) const
 
   return crc8[0U] == header[DSTAR_HEADER_LENGTH_BYTES - 2U] && crc8[1U] == header[DSTAR_HEADER_LENGTH_BYTES - 1U];
 }
+
+#endif
+

DStarRX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,10 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DSTAR)
+
 #if !defined(DSTARRX_H)
 #define  DSTARRX_H
 
-#include "Config.h"
 #include "DStarDefines.h"
 
 enum DSRX_STATE {
@@ -37,13 +40,21 @@ public:
   void reset();
 
 private:
-  uint32_t     m_pll;
-  bool         m_prev;
   DSRX_STATE   m_rxState;
-  uint32_t     m_patternBuffer;
-  uint8_t      m_rxBuffer[100U];
-  unsigned int m_rxBufferBits;
-  unsigned int m_dataBits;
+  uint64_t     m_bitBuffer[DSTAR_RADIO_SYMBOL_LENGTH];
+  q15_t        m_headerBuffer[DSTAR_FEC_SECTION_LENGTH_SAMPLES + 2U * DSTAR_RADIO_SYMBOL_LENGTH];
+  q15_t        m_dataBuffer[DSTAR_DATA_LENGTH_SAMPLES];
+  uint16_t     m_bitPtr;
+  uint16_t     m_headerPtr;
+  uint16_t     m_dataPtr;
+  uint16_t     m_startPtr;
+  uint16_t     m_syncPtr;
+  uint16_t     m_minSyncPtr;
+  uint16_t     m_maxSyncPtr;
+  q31_t        m_maxFrameCorr;
+  q31_t        m_maxDataCorr;
+  uint16_t     m_frameCount;
+  uint8_t      m_countdown;
   unsigned int m_mar;
   int          m_pathMetric[4U];
   unsigned int m_pathMemory0[42U];
@@ -54,9 +65,12 @@ private:
   uint32_t     m_rssiAccum;
   uint16_t     m_rssiCount;
   
-  void    processNone(bool bit);
-  void    processHeader(bool bit);
-  void    processData(bool bit);
+  void    processNone(q15_t sample);
+  void    processHeader(q15_t sample);
+  void    processData();
+  bool    correlateFrameSync();
+  bool    correlateDataSync();
+  void    samplesToBits(const q15_t* inBuffer, uint16_t start, uint16_t count, uint8_t* outBuffer, uint16_t limit);
   void    writeRSSIHeader(unsigned char* header);
   void    writeRSSIData(unsigned char* data);
   bool    rxHeader(uint8_t* in, uint8_t* out);
@@ -68,3 +82,5 @@ private:
 
 #endif
 
+#endif
+

DStarTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -18,6 +18,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_DSTAR)
+
 #include "Globals.h"
 #include "DStarTX.h"
 
@@ -198,7 +201,7 @@ m_txDelay(60U)       // 100ms
 {
   ::memset(m_modState, 0x00U, 20U * sizeof(q15_t));
 
-  m_modFilter.L           = DSTAR_RADIO_BIT_LENGTH;
+  m_modFilter.L           = DSTAR_RADIO_SYMBOL_LENGTH;
   m_modFilter.phaseLength = GAUSSIAN_0_35_FILTER_PHASE_LEN;
   m_modFilter.pCoeffs     = GAUSSIAN_0_35_FILTER;
   m_modFilter.pState      = m_modState;
@@ -217,11 +220,12 @@ void CDStarTX::process()
         m_poBuffer[m_poLen++] = BIT_SYNC;
     } else {
       // Pop the type byte off
-      m_buffer.get();
+      uint8_t dummy;
+      m_buffer.get(dummy);
 
       uint8_t header[DSTAR_HEADER_LENGTH_BYTES];
       for (uint8_t i = 0U; i < DSTAR_HEADER_LENGTH_BYTES; i++)
-        header[i] = m_buffer.get();
+        m_buffer.get(header[i]);
 
       uint8_t buffer[86U];
       txHeader(header, buffer + 2U);
@@ -239,21 +243,23 @@ void CDStarTX::process()
  
   if (type == DSTAR_DATA && m_poLen == 0U) {
     // Pop the type byte off
-    m_buffer.get();
+    uint8_t dummy;
+    m_buffer.get(dummy);
 
     for (uint8_t i = 0U; i < DSTAR_DATA_LENGTH_BYTES; i++)
-      m_poBuffer[m_poLen++] = m_buffer.get();
+      m_buffer.get(m_poBuffer[m_poLen++]);
 
     m_poPtr = 0U;
   }
 
   if (type == DSTAR_EOT && m_poLen == 0U) {
     // Pop the type byte off
-    m_buffer.get();
+    uint8_t dummy;
+    m_buffer.get(dummy);
 
     for (uint8_t j = 0U; j < 3U; j++) {
-      for (uint8_t i = 0U; i < DSTAR_EOT_LENGTH_BYTES; i++)
-        m_poBuffer[m_poLen++] = DSTAR_EOT_BYTES[i];
+      for (uint8_t i = 0U; i < DSTAR_END_SYNC_LENGTH_BYTES; i++)
+        m_poBuffer[m_poLen++] = DSTAR_END_SYNC_BYTES[i];
     }
      
     m_poPtr = 0U;
@@ -262,11 +268,11 @@ void CDStarTX::process()
   if (m_poLen > 0U) {
     uint16_t space = io.getSpace();
     
-    while (space > (8U * DSTAR_RADIO_BIT_LENGTH)) {
+    while (space > (8U * DSTAR_RADIO_SYMBOL_LENGTH)) {
       uint8_t c = m_poBuffer[m_poPtr++];
       writeByte(c);
 
-      space -= 8U * DSTAR_RADIO_BIT_LENGTH;
+      space -= 8U * DSTAR_RADIO_SYMBOL_LENGTH;
       
       if (m_poPtr >= m_poLen) {
         m_poPtr = 0U;
@@ -277,7 +283,7 @@ void CDStarTX::process()
   }
 }
 
-uint8_t CDStarTX::writeHeader(const uint8_t* header, uint8_t length)
+uint8_t CDStarTX::writeHeader(const uint8_t* header, uint16_t length)
 {
   if (length != DSTAR_HEADER_LENGTH_BYTES)
     return 4U;
@@ -296,7 +302,7 @@ uint8_t CDStarTX::writeHeader(const uint8_t* header, uint8_t length)
   return 0U;
 }
 
-uint8_t CDStarTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CDStarTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != DSTAR_DATA_LENGTH_BYTES)
     return 4U;
@@ -412,7 +418,7 @@ void CDStarTX::txHeader(const uint8_t* in, uint8_t* out) const
 void CDStarTX::writeByte(uint8_t c)
 {
   q15_t inBuffer[8U];
-  q15_t outBuffer[DSTAR_RADIO_BIT_LENGTH * 8U];
+  q15_t outBuffer[DSTAR_RADIO_SYMBOL_LENGTH * 8U];
 
   uint8_t mask = 0x01U;
 
@@ -427,7 +433,7 @@ void CDStarTX::writeByte(uint8_t c)
 
   ::arm_fir_interpolate_q15(&m_modFilter, inBuffer, outBuffer, 8U);
   
-  io.write(STATE_DSTAR, outBuffer, DSTAR_RADIO_BIT_LENGTH * 8U);
+  io.write(STATE_DSTAR, outBuffer, DSTAR_RADIO_SYMBOL_LENGTH * 8U);
 }
 
 void CDStarTX::setTXDelay(uint8_t delay)
@@ -443,3 +449,5 @@ uint8_t CDStarTX::getSpace() const
   return m_buffer.getSpace() / (DSTAR_DATA_LENGTH_BYTES + 1U);
 }
 
+#endif
+

DStarTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,19 +16,21 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_DSTAR)
+
 #if !defined(DSTARTX_H)
 #define  DSTARTX_H
 
-#include "Config.h"
-
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CDStarTX {
 public:
   CDStarTX();
 
-  uint8_t writeHeader(const uint8_t* header, uint8_t length);
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeHeader(const uint8_t* header, uint16_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
   uint8_t writeEOT();
 
   void process();
@@ -38,7 +40,7 @@ public:
   uint8_t getSpace() const;
 
 private:
-  CSerialRB                        m_buffer;
+  CRingBuffer<uint8_t>             m_buffer;
   arm_fir_interpolate_instance_q15 m_modFilter;
   q15_t                            m_modState[20U];    // blockSize + phaseLength - 1, 8 + 9 - 1 plus some spare
   uint8_t                          m_poBuffer[600U];
@@ -52,3 +54,5 @@ private:
 
 #endif
 
+#endif
+

Debug.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2021 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -27,6 +27,7 @@
 #define  DEBUG3(a,b,c)      serial.writeDebug((a),(b),(c))
 #define  DEBUG4(a,b,c,d)    serial.writeDebug((a),(b),(c),(d))
 #define  DEBUG5(a,b,c,d,e)  serial.writeDebug((a),(b),(c),(d),(e))
+#define  DEBUG_DUMP(a,b)    serial.writeDebugDump((a),(b))
 
 #endif
 

FM.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020,2021 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,39 +16,46 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_FM)
+
 #if !defined(FM_H)
 #define  FM_H
 
-#include "Config.h"
-
 #include "FMBlanking.h"
 #include "FMCTCSSRX.h"
 #include "FMCTCSSTX.h"
 #include "FMTimeout.h"
 #include "FMKeyer.h"
 #include "FMTimer.h"
-#include "FMRB.h"
+#include "RingBuffer.h"
 #include "FMDirectForm1.h"
-#include "FMDownsampler.h"
+#include "FMDownSampler.h"
+#include "FMUpSampler.h"
+#include "FMNoiseSquelch.h"
 
 enum FM_STATE {
   FS_LISTENING,
-  FS_KERCHUNK,
-  FS_RELAYING,
-  FS_RELAYING_WAIT,
-  FS_TIMEOUT,
-  FS_TIMEOUT_WAIT,
+  FS_KERCHUNK_RF,
+  FS_RELAYING_RF,
+  FS_RELAYING_WAIT_RF,
+  FS_TIMEOUT_RF,
+  FS_TIMEOUT_WAIT_RF,
+  FS_KERCHUNK_EXT,
+  FS_RELAYING_EXT,
+  FS_RELAYING_WAIT_EXT,
+  FS_TIMEOUT_EXT,
+  FS_TIMEOUT_WAIT_EXT,
   FS_HANG
 };
 
 
-
-
 class CFM {
 public:
   CFM();
 
-  void samples(bool cos, const q15_t* samples, uint8_t length);
+  void samples(bool cos, q15_t* samples, uint8_t length);
 
   void process();
 
@@ -56,13 +63,20 @@ public:
 
   uint8_t setCallsign(const char* callsign, uint8_t speed, uint16_t frequency, uint8_t time, uint8_t holdoff, uint8_t highLevel, uint8_t lowLevel, bool callsignAtStart, bool callsignAtEnd, bool callsignAtLatch);
   uint8_t setAck(const char* rfAck, uint8_t speed, uint16_t frequency, uint8_t minTime, uint16_t delay, uint8_t level);
-  uint8_t setMisc(uint16_t timeout, uint8_t timeoutLevel, uint8_t ctcssFrequency, uint8_t ctcssHighThreshold, uint8_t ctcssLowThreshold, uint8_t ctcssLevel, uint8_t kerchunkTime, bool kerchunkTX, uint8_t hangTime, bool useCOS, bool cosInvert, uint8_t rfAudioBoost, uint8_t maxDev, uint8_t rxLevel);
+  uint8_t setMisc(uint16_t timeout, uint8_t timeoutLevel, uint8_t ctcssFrequency, uint8_t ctcssHighThreshold, uint8_t ctcssLowThreshold, uint8_t ctcssLevel, uint8_t kerchunkTime, uint8_t hangTime, uint8_t accessMode, bool linkMode, bool cosInvert, bool noiseSquelch, uint8_t squelchHighThreshold, uint8_t squelchLowThreshold, uint8_t rfAudioBoost, uint8_t maxDev, uint8_t rxLevel);
+  uint8_t setExt(const char* ack, uint8_t audioBoost, uint8_t speed, uint16_t frequency, uint8_t level);
+
+  uint8_t getSpace() const;
+
+  uint8_t writeData(const uint8_t* data, uint8_t length);
 
 private:
   CFMKeyer             m_callsign;
   CFMKeyer             m_rfAck;
+  CFMKeyer             m_extAck;
   CFMCTCSSRX           m_ctcssRX;
   CFMCTCSSTX           m_ctcssTX;
+  CFMNoiseSquelch      m_squelch;
   CFMTimeout           m_timeoutTone;
   FM_STATE             m_state;
   bool                 m_callsignAtStart;
@@ -72,30 +86,59 @@ private:
   CFMTimer             m_timeoutTimer;
   CFMTimer             m_holdoffTimer;
   CFMTimer             m_kerchunkTimer;
-  bool                 m_kerchunkTX;
   CFMTimer             m_ackMinTimer;
   CFMTimer             m_ackDelayTimer;
   CFMTimer             m_hangTimer;
+  CFMTimer             m_statusTimer;
+  CFMTimer             m_reverseTimer;
+  bool                 m_needReverse;
   CFMDirectFormI       m_filterStage1;
   CFMDirectFormI       m_filterStage2;
   CFMDirectFormI       m_filterStage3;
   CFMBlanking          m_blanking;
-  bool                 m_useCOS;
+  uint8_t              m_accessMode;
+  bool                 m_linkMode;
   bool                 m_cosInvert;
+  bool                 m_noiseSquelch;
   q15_t                m_rfAudioBoost;
-  CFMDownsampler       m_downsampler;
+  q15_t                m_extAudioBoost;
+  CFMDownSampler       m_downSampler;
+  bool                 m_extEnabled;
   q15_t                m_rxLevel;
-  CFMRB                m_inputRB;
-  CFMRB                m_outputRB;
+  CRingBuffer<q15_t>   m_inputRFRB;
+  CRingBuffer<q15_t>   m_outputRFRB;
+  CFMUpSampler         m_inputExtRB;
+  bool                 m_rfSignal;
+  bool                 m_extSignal;
 
-  void stateMachine(bool validSignal);
-  void listeningState(bool validSignal);
-  void kerchunkState(bool validSignal);
-  void relayingState(bool validSignal);
-  void relayingWaitState(bool validSignal);
-  void timeoutState(bool validSignal);
-  void timeoutWaitState(bool validSignal);
-  void hangState(bool validSignal);
+  void stateMachine(bool validRFSignal, bool validExtSignal);
+
+  void duplexStateMachine(bool validRFSignal, bool validExtSignal);
+  void listeningStateDuplex(bool validRFSignal, bool validExtSignal);
+  void kerchunkRFStateDuplex(bool validSignal);
+  void relayingRFStateDuplex(bool validSignal);
+  void relayingRFWaitStateDuplex(bool validSignal);
+  void timeoutRFStateDuplex(bool validSignal);
+  void timeoutRFWaitStateDuplex(bool validSignal);
+  void kerchunkExtStateDuplex(bool validSignal);
+  void relayingExtStateDuplex(bool validSignal);
+  void relayingExtWaitStateDuplex(bool validSignal);
+  void timeoutExtStateDuplex(bool validSignal);
+  void timeoutExtWaitStateDuplex(bool validSignal);
+  void hangStateDuplex(bool validRFSignal, bool validExtSignal);
+
+  void simplexStateMachine(bool validRFSignal, bool validExtSignal);
+  void listeningStateSimplex(bool validRFSignal, bool validExtSignal);
+  void relayingRFStateSimplex(bool validSignal);
+  void relayingRFWaitStateSimplex(bool validSignal);
+  void timeoutRFStateSimplex(bool validSignal);
+  void timeoutRFWaitStateSimplex(bool validSignal);
+  void relayingExtStateSimplex(bool validSignal);
+  void relayingExtWaitStateSimplex(bool validSignal);
+  void timeoutExtStateSimplex(bool validSignal);
+  void timeoutExtWaitStateSimplex(bool validSignal);
+
+  void linkStateMachine(bool validRFSignal, bool validExtSignal);
 
   void clock(uint8_t length);
 
@@ -107,3 +150,6 @@ private:
 };
 
 #endif
+
+#endif
+

FMBlanking.cpp

@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_FM)
+
 #include "Globals.h"
 #include "FMBlanking.h"
 
@@ -80,3 +83,6 @@ q15_t CFMBlanking::process(q15_t sample)
 
   return sample;
 }
+
+#endif
+

FMBlanking.h

@@ -16,11 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_FM)
+
 #if !defined(FMBlanking_H)
 #define  FMBlanking_H
 
-#include "Config.h"
-
 class CFMBlanking {
 public:
   CFMBlanking();
@@ -39,3 +41,6 @@ private:
 };
 
 #endif
+
+#endif
+

FMCTCSSRX.cpp

@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_FM)
+
 #include "Globals.h"
 #include "FMCTCSSRX.h"
 
@@ -87,7 +90,7 @@ m_lowThreshold(0),
 m_count(0U),
 m_q0(0),
 m_q1(0),
-m_result(CTS_NONE)
+m_state(false)
 {
 }
 
@@ -111,13 +114,11 @@ uint8_t CFMCTCSSRX::setParams(uint8_t frequency, uint8_t highThreshold, uint8_t
   return 0U;
 }
 
-uint8_t CFMCTCSSRX::process(q15_t sample)
+bool CFMCTCSSRX::process(q15_t sample)
 {
   //get more dynamic into the decoder by multiplying the sample by 1.5
   q31_t sample31 = q31_t(sample) +  (q31_t(sample) >> 1);
 
-  m_result &= ~CTS_READY;
-
   q31_t q2 = m_q1;
   m_q1 = m_q0;
 
@@ -149,33 +150,32 @@ uint8_t CFMCTCSSRX::process(q15_t sample)
     // value = m_q0 * m_q0 + m_q1 * m_q1 - m_q0 * m_q1 * m_coeffDivTwo * 2
     q31_t value = t2 + t4 - t9;
 
-    bool previousCTCSSValid = CTCSS_VALID(m_result);
+    bool previousState = m_state;
 
     q31_t threshold = m_highThreshold;
-    if (previousCTCSSValid)
+    if (previousState)
       threshold = m_lowThreshold;
 
-    m_result |= CTS_READY;
-    if (value >= threshold)
-      m_result |= CTS_VALID;
-    else
-      m_result &= ~CTS_VALID;
+    m_state = value >= threshold;
 
-    if (previousCTCSSValid != CTCSS_VALID(m_result))
-      DEBUG4("CTCSS Value / Threshold / Valid", value, threshold, CTCSS_VALID(m_result));
+    if (previousState != m_state)
+      DEBUG4("CTCSS Value / Threshold / Valid", value, threshold, m_state);
 
     m_count = 0U;
     m_q0 = 0;
     m_q1 = 0;
   }
 
-  return m_result;
+  return m_state;
 }
 
 void CFMCTCSSRX::reset()
 {
   m_q0 = 0;
   m_q1 = 0;
-  m_result = CTS_NONE;
-  m_count  = 0U;
+  m_state = false;
+  m_count = 0U;
 }
+
+#endif
+

FMCTCSSRX.h

@@ -16,19 +16,12 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
-#if !defined(FMCTCSSRX_H)
-#define  FMCTCSSRX_H
-
 #include "Config.h"
 
-const uint8_t CTS_NONE  = 0U;
-const uint8_t CTS_READY = 1U;
-const uint8_t CTS_VALID = 2U;
+#if defined(MODE_FM)
 
-#define CTCSS_READY(a) ((a & CTS_READY) != 0)
-#define CTCSS_NOT_READY(a) ((a & CTS_READY) == 0)
-#define CTCSS_VALID(a) ((a & CTS_VALID) != 0)
-#define CTCSS_NOT_VALID(a) ((a & CTS_VALID) == 0)
+#if !defined(FMCTCSSRX_H)
+#define  FMCTCSSRX_H
 
 class CFMCTCSSRX {
 public:
@@ -36,7 +29,7 @@ public:
 
   uint8_t setParams(uint8_t frequency, uint8_t highThreshold, uint8_t lowThreshold);
   
-  uint8_t process(q15_t sample);
+  bool process(q15_t sample);
 
   void reset();
 
@@ -47,7 +40,10 @@ private:
   uint16_t m_count;
   q31_t    m_q0;
   q31_t    m_q1;
-  uint8_t  m_result;
+  bool     m_state;
 };
 
 #endif
+
+#endif
+

FMCTCSSTX.cpp

@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_FM)
+
 #include "Globals.h"
 #include "FMCTCSSTX.h"
 
@@ -115,11 +118,17 @@ uint8_t CFMCTCSSTX::setParams(uint8_t frequency, uint8_t level)
   return 0U;
 }
 
-q15_t CFMCTCSSTX::getAudio()
+q15_t CFMCTCSSTX::getAudio(bool reverse)
 {
   q15_t sample = m_values[m_n++];
-  if(m_n >= m_length)
+  if (m_n >= m_length)
     m_n = 0U;
   
-  return sample;
+  if (reverse)
+    return -sample;
+  else
+    return sample;
 }
+
+#endif
+

FMCTCSSTX.h

@@ -16,18 +16,20 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_FM)
+
 #if !defined(FMCTCSSTX_H)
 #define  FMCTCSSTX_H
 
-#include "Config.h"
-
 class CFMCTCSSTX {
 public:
   CFMCTCSSTX();
 
   uint8_t setParams(uint8_t frequency, uint8_t level);
 
-  q15_t getAudio();
+  q15_t getAudio(bool reverse);
 
 private:
   q15_t*   m_values;
@@ -36,3 +38,6 @@ private:
 };
 
 #endif
+
+#endif
+

FMDirectForm1.h

@@ -29,7 +29,11 @@ THE SOFTWARE.
 
 // based on https://raw.githubusercontent.com/berndporr/iir_fixed_point/master/DirectFormI.h
 
-#include "Globals.h"
+#include "Config.h"
+
+#if defined(MODE_FM)
+
+#include <cstdint>
 
 #ifndef DIRECTFORMI_H_
 #define DIRECTFORMI_H_
@@ -108,4 +112,7 @@ private:
 	q31_t c_a1,c_a2; // IIR
 };
 
-#endif /* DIRECTFORMI_H */
+#endif /* DIRECTFORMI_H */
+
+#endif
+

FMDownSampler.cpp

@@ -0,0 +1,80 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_FM)
+
+#include "FMDownSampler.h"
+
+CFMDownSampler::CFMDownSampler(uint16_t length) :
+m_ringBuffer(length),
+m_samplePack(0U),
+m_samplePackPointer(NULL),
+m_sampleIndex(0U)
+{
+  m_samplePackPointer = (uint8_t*)&m_samplePack;
+}
+
+void CFMDownSampler::addSample(q15_t sample)
+{
+  uint32_t usample = uint32_t(int32_t(sample) + 2048);
+  //only take one of three samples
+  switch(m_sampleIndex){
+    case 0:
+      m_samplePack = usample << 12;
+    break;
+    case 3:{
+      m_samplePack |= usample;
+      
+      //we did not use MSB; skip it
+      TSamplePairPack pair{m_samplePackPointer[0U], m_samplePackPointer[1U], m_samplePackPointer[2U]}; 
+
+      m_ringBuffer.put(pair);
+
+      m_samplePack = 0U;//reset the sample pack
+    }
+    break;
+    default:
+        //Just skip this sample
+    break;
+  }
+
+  m_sampleIndex++;
+  if (m_sampleIndex >= 6U)//did we pack two samples ?
+      m_sampleIndex = 0U;  
+}
+
+bool CFMDownSampler::getPackedData(TSamplePairPack& data)
+{
+  return m_ringBuffer.get(data);
+}
+
+uint16_t CFMDownSampler::getData()
+{
+  return m_ringBuffer.getData();
+}
+
+void CFMDownSampler::reset()
+{
+  m_sampleIndex = 0U;
+}
+
+#endif
+

FMDownSampler.h

@@ -17,27 +17,36 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_FM)
+
 #if !defined(FMDOWNSAMPLER_H)
 #define FMDOWNSAMPLER_H
 
-#include "Config.h"
-#include "FMDownsampleRB.h"
+#include "RingBuffer.h"
+#include "FMSamplePairPack.h"
 
-class CFMDownsampler {
+class CFMDownSampler {
 public:
-  CFMDownsampler(uint16_t length);
+  CFMDownSampler(uint16_t length);
+
   void addSample(q15_t sample);
-  inline bool getPackedData(uint8_t& data){ return m_ringBuffer.get(data); };
-  inline bool hasOverflowed() { return m_ringBuffer.hasOverflowed(); };
+
+  bool getPackedData(TSamplePairPack& data);
+
+  uint16_t getData();
+
+  void reset();
 
 private:
-  CFMDownsampleRB m_ringBuffer;
-  union {
-    int32_t m_samplePack;
-    int8_t  m_samplePackBytes[4];
-  };
-  uint8_t m_packIndex;
-  uint8_t m_downSampleIndex;
+  CRingBuffer<TSamplePairPack> m_ringBuffer;
+  uint32_t                     m_samplePack;
+  uint8_t*                     m_samplePackPointer;
+  uint8_t                      m_sampleIndex;
 };
 
 #endif
+
+#endif
+

FMDownsampler.cpp

@@ -1,63 +0,0 @@
-/*
- *   Copyright (C) 2020 by Jonathan Naylor G4KLX
- *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
- *
- *   This program is free software; you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *   GNU General Public License for more details.
- *
- *   You should have received a copy of the GNU General Public License
- *   along with this program; if not, write to the Free Software
- *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#include "Config.h"
-#include "FMDownsampler.h"
-
-
-CFMDownsampler::CFMDownsampler(uint16_t length) :
-m_ringBuffer(length),//length might need tweaking
-m_packIndex(0),
-m_downSampleIndex(0)
-{
-    m_samplePack = 0;
-}
-
-void CFMDownsampler::addSample(q15_t sample)
-{
-    //only take one of three samples
-    if(m_downSampleIndex == 0) {
-      switch(m_packIndex){
-        case 0:
-          m_samplePack = int32_t(sample) << 12;
-        break;
-        case 1:{
-            m_samplePack |= int32_t(sample);
-            
-            //we did not use MSB; skip it
-            m_ringBuffer.put(m_samplePackBytes[1]); 
-            m_ringBuffer.put(m_samplePackBytes[2]); 
-            m_ringBuffer.put(m_samplePackBytes[3]); 
-
-            m_samplePack = 0;
-        }
-        break;
-        default:
-            //should never happen
-        break;
-        }
-        m_packIndex++;
-        if(m_packIndex >= 2)
-            m_packIndex = 0;  
-    }
-
-    m_downSampleIndex++;
-    if(m_downSampleIndex >= 3)
-        m_downSampleIndex = 0;
-}

FMKeyer.cpp

@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_FM)
+
 #include "Globals.h"
 #include "FMKeyer.h"
 
@@ -214,3 +217,6 @@ bool CFMKeyer::isRunning() const
 {
   return m_poPos > 0U || m_dotPos > 0U || m_audioPos > 0U;
 }
+
+#endif
+

FMKeyer.h

@@ -16,11 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_FM)
+
 #if !defined(FMKeyer_H)
 #define  FMKeyer_H
 
-#include "Config.h"
-
 class CFMKeyer {
 public:
   CFMKeyer();
@@ -52,3 +54,6 @@ private:
 };
 
 #endif
+
+#endif
+

FMNoiseSquelch.cpp

@@ -0,0 +1,133 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_FM)
+
+#include "Globals.h"
+#include "FMNoiseSquelch.h"
+
+// 4500Hz centre frequency
+const q31_t COEFF_DIV_TWO = 821806413;
+
+// 400Hz bandwidth
+const uint16_t N = 24000U / 400U;
+
+CFMNoiseSquelch::CFMNoiseSquelch() :
+m_highThreshold(0),
+m_lowThreshold(0),
+m_count(0U),
+m_q0(0),
+m_q1(0),
+m_state(false),
+m_validCount(0U)
+{
+
+}
+
+void CFMNoiseSquelch::setParams(uint8_t highThreshold, uint8_t lowThreshold)
+{
+  m_highThreshold = q31_t(highThreshold);
+  m_lowThreshold  = q31_t(lowThreshold);
+}
+
+bool CFMNoiseSquelch::process(q15_t sample)
+{
+  //get more dynamic into the decoder by multiplying the sample by 64
+  q31_t sample31 = q31_t(sample) << 6; //+  (q31_t(sample) >> 1);
+
+  q31_t q2 = m_q1;
+  m_q1 = m_q0;
+
+  // Q31 multiplication, t3 = m_coeffDivTwo * 2 * m_q1
+  q63_t t1 = COEFF_DIV_TWO * m_q1;
+  q31_t t2 = __SSAT((t1 >> 31), 31);
+  q31_t t3 = t2 * 2;
+
+  // m_q0 = m_coeffDivTwo * m_q1 * 2 - q2 + sample
+  m_q0 = t3 - q2 + sample31;
+
+  m_count++;
+  if (m_count == N) {
+    // Q31 multiplication, t2 = m_q0 * m_q0
+    q63_t t1 = q63_t(m_q0) * q63_t(m_q0);
+    q31_t t2 = __SSAT((t1 >> 31), 31);
+
+    // Q31 multiplication, t4 = m_q0 * m_q0
+    q63_t t3 = q63_t(m_q1) * q63_t(m_q1);
+    q31_t t4 = __SSAT((t3 >> 31), 31);
+
+    // Q31 multiplication, t9 = m_q0 * m_q1 * m_coeffDivTwo * 2
+    q63_t t5 = q63_t(m_q0) * q63_t(m_q1);
+    q31_t t6 = __SSAT((t5 >> 31), 31);
+    q63_t t7 = t6 * COEFF_DIV_TWO;
+    q31_t t8 = __SSAT((t7 >> 31), 31);
+    q31_t t9  = t8 * 2;
+
+    // value = m_q0 * m_q0 + m_q1 * m_q1 - m_q0 * m_q1 * m_coeffDivTwo * 2
+    q31_t value = t2 + t4 - t9;
+
+    bool previousState = m_state;
+
+    q31_t threshold = m_highThreshold;
+    if (previousState)
+      threshold = m_lowThreshold;
+
+    if (!m_state) {
+      if (value < threshold)
+        m_validCount++;
+      else
+        m_validCount = 0U;
+    }
+
+    if (m_state) {
+      if (value >= threshold)
+        m_invalidCount++;
+      else
+        m_invalidCount = 0U;
+    }
+
+    m_state = m_validCount >= 10U && m_invalidCount < 10U;
+
+    if(previousState && !m_state)
+      m_invalidCount = 0U;
+
+    if (previousState != m_state) {
+      DEBUG4("Noise Squelch Value / Threshold / Valid", value, threshold, m_state);
+      DEBUG3("Valid Count / Invalid Count", m_validCount, m_invalidCount);
+    }
+
+    m_count = 0U;
+    m_q0 = 0;
+    m_q1 = 0;
+  }
+
+  return m_state;
+}
+
+void CFMNoiseSquelch::reset()
+{
+  m_q0 = 0;
+  m_q1 = 0;
+  m_state = false;
+  m_count = 0U;
+}
+
+#endif
+

FMNoiseSquelch.h

@@ -0,0 +1,50 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_FM)
+
+#if !defined(FMNOISESQUELCH_H)
+#define  FMNOISESQUELCH_H
+
+class CFMNoiseSquelch {
+public:
+  CFMNoiseSquelch();
+
+  void setParams(uint8_t highThreshold, uint8_t lowThreshold);
+  
+  bool process(q15_t sample);
+
+  void reset();
+
+private:
+  q31_t    m_highThreshold;
+  q31_t    m_lowThreshold;
+  uint16_t m_count;
+  q31_t    m_q0;
+  q31_t    m_q1;
+  bool     m_state;
+  uint8_t  m_validCount;
+  uint8_t  m_invalidCount;
+};
+
+#endif
+
+#endif
+

FMRB.cpp

@@ -1,110 +0,0 @@
-/*
-TX fifo control - Copyright (C) KI6ZUM 2015
-Copyright (C) 2015,2016,2020 by Jonathan Naylor G4KLX
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public
-License as published by the Free Software Foundation; either
-version 2 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the
-Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
-Boston, MA  02110-1301, USA.
-*/
-
-#include "FMRB.h"
-
-CFMRB::CFMRB(uint16_t length) :
-m_length(length),
-m_head(0U),
-m_tail(0U),
-m_full(false),
-m_overflow(false)
-{
-  m_samples = new q15_t[length];
-}
-
-uint16_t CFMRB::getSpace() const
-{
-  uint16_t n = 0U;
-
-  if (m_tail == m_head)
-    n = m_full ? 0U : m_length;
-  else if (m_tail < m_head)
-    n = m_length - m_head + m_tail;
-  else
-    n = m_tail - m_head;
-
-  if (n > m_length)
-    n = 0U;
-
-  return n;
-}
-
-uint16_t CFMRB::getData() const
-{
-  if (m_tail == m_head)
-    return m_full ? m_length : 0U;
-  else if (m_tail < m_head)
-    return m_head - m_tail;
-  else
-    return m_length - m_tail + m_head;
-}
-
-bool CFMRB::put(q15_t sample)
-{
-  if (m_full) {
-    m_overflow = true;
-    return false;
-  }
-
-  m_samples[m_head] = sample;
-
-  m_head++;
-  if (m_head >= m_length)
-    m_head = 0U;
-
-  if (m_head == m_tail)
-    m_full = true;
-
-  return true;
-}
-
-bool CFMRB::get(q15_t& sample)
-{
-  if (m_head == m_tail && !m_full)
-    return false;
-
-  sample = m_samples[m_tail];
-
-  m_full = false;
-
-  m_tail++;
-  if (m_tail >= m_length)
-    m_tail = 0U;
-
-  return true;
-}
-
-bool CFMRB::hasOverflowed()
-{
-  bool overflow = m_overflow;
-
-  m_overflow = false;
-
-  return overflow;
-}
-
-void CFMRB::reset()
-{
-  m_head = 0U;
-  m_tail = 0U;
-  m_full     = false;
-  m_overflow = false;
-}

FMRB.h

@@ -1,72 +0,0 @@
-/*
-Serial fifo control - Copyright (C) KI6ZUM 2015
-Copyright (C) 2015,2016,2020 by Jonathan Naylor G4KLX
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public
-License as published by the Free Software Foundation; either
-version 2 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the
-Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
-Boston, MA  02110-1301, USA.
-*/
-
-#if !defined(FMRB_H)
-#define  FMRB_H
-
-#if defined(STM32F4XX)
-#include "stm32f4xx.h"
-#elif defined(STM32F7XX)
-#include "stm32f7xx.h"
-#elif defined(STM32F105xC)
-#include "stm32f1xx.h"
-#include <cstddef>
-#else
-#include <Arduino.h>
-#endif
-
-#if defined(__SAM3X8E__) || defined(STM32F105xC)
-#define  ARM_MATH_CM3
-#elif defined(STM32F7XX)
-#define  ARM_MATH_CM7
-#elif defined(STM32F4XX) || defined(__MK20DX256__) || defined(__MK64FX512__) || defined(__MK66FX1M0__)
-#define  ARM_MATH_CM4
-#else
-#error "Unknown processor type"
-#endif
-
-#include <arm_math.h>
-
-class CFMRB {
-public:
-  CFMRB(uint16_t length);
-  
-  uint16_t getSpace() const;
-  
-  uint16_t getData() const;
-
-  bool put(q15_t sample);
-
-  bool get(q15_t& sample);
-
-  bool hasOverflowed();
-
-  void reset();
-
-private:
-  uint16_t          m_length;
-  volatile q15_t*   m_samples;
-  volatile uint16_t m_head;
-  volatile uint16_t m_tail;
-  volatile bool     m_full;
-  bool              m_overflow;
-};
-
-#endif

FMSamplePairPack.h

@@ -0,0 +1,36 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_FM)
+
+#if !defined(TSAMPLEPACK_H)
+#define TSAMPLEPACK_H
+
+struct TSamplePairPack {
+  uint8_t byte0;
+  uint8_t byte1;
+  uint8_t byte2;
+};
+
+#endif
+
+#endif
+

FMTimeout.cpp

@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_FM)
+
 #include "Globals.h"
 #include "FMTimeout.h"
 
@@ -36,24 +39,22 @@ m_n(0U)
 
 void CFMTimeout::setParams(uint8_t level)
 {
-  m_level = q15_t(level * 128);
+  m_level = q15_t(level * 5);
 }
 
 q15_t CFMTimeout::getAudio()
 {
-  q15_t sample = 0U;
+  q15_t sample = 0;
   if (!m_running)
     return sample;
 
-  if (m_pos > 12000U) {
-    q31_t sample = BUSY_AUDIO[m_n] * m_level;
-    sample = q15_t(__SSAT((sample >> 15), 16));
+  if (m_pos >= 12000U) {
+    q31_t sample31 = BUSY_AUDIO[m_n] * m_level;
+    sample = q15_t(__SSAT((sample31 >> 15), 16));
 
     m_n++;
     if (m_n >= BUSY_AUDIO_LEN)
       m_n = 0U;
-  } else {
-    sample = 0U;
   }
 
   m_pos++;
@@ -74,3 +75,6 @@ void CFMTimeout::stop()
 {
   m_running = false;
 }
+
+#endif
+

FMTimeout.h

@@ -16,11 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_FM)
+
 #if !defined(FMTimeout_H)
 #define  FMTimeout_H
 
-#include "Config.h"
-
 class CFMTimeout {
 public:
   CFMTimeout();
@@ -40,3 +42,6 @@ private:
 };
 
 #endif
+
+#endif
+

FMTimer.cpp

@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_FM)
+
 #include "Globals.h"
 #include "FMTimer.h"
 
@@ -68,3 +71,6 @@ bool CFMTimer::hasExpired() const
 
   return false;
 }
+
+#endif
+

FMTimer.h

@@ -16,11 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_FM)
+
 #if !defined(FMTimer_H)
 #define  FMTimer_H
 
-#include "Config.h"
-
 class CFMTimer {
 public:
   CFMTimer();
@@ -45,3 +47,6 @@ private:
 };
 
 #endif
+
+#endif
+

FMUpSampler.cpp

@@ -0,0 +1,104 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_FM)
+
+#include "FMUpSampler.h"
+
+const uint32_t FM_UPSAMPLE_MASK = 0x00000FFFU;
+
+CFMUpSampler::CFMUpSampler() :
+m_upSampleIndex(0),
+m_pack(0U),
+m_packPointer(NULL),
+m_samples(3600U), //300ms of 12 bit 8kHz audio
+m_running(false)
+{
+  m_packPointer = (uint8_t*)&m_pack;
+}
+
+void CFMUpSampler::reset()
+{
+    m_upSampleIndex = 0U;
+    m_pack = 0U;
+    m_samples.reset();
+    m_running = false;
+}
+
+void CFMUpSampler::addData(const uint8_t* data, uint16_t length)
+{
+  TSamplePairPack* packPointer = (TSamplePairPack*)data;
+  TSamplePairPack* packPointerEnd = packPointer + (length / 3U);
+  while(packPointer != packPointerEnd) {
+    m_samples.put(*packPointer);
+    packPointer++;
+  }
+  if(!m_running)
+    m_running = m_samples.getData() > 300U;//75ms of audio
+}
+
+bool CFMUpSampler::getSample(q15_t& sample)
+{
+  if(!m_running)
+    return false;
+
+  switch (m_upSampleIndex)
+  {
+  case 0: {
+    TSamplePairPack pairPack;
+    if(!m_samples.get(pairPack)) {
+      m_running = false;
+      return false;
+    }
+      
+    m_pack = 0U;
+    m_packPointer = (uint8_t*)&m_pack;
+
+    m_packPointer[0U] = pairPack.byte0;
+    m_packPointer[1U] = pairPack.byte1;
+    m_packPointer[2U] = pairPack.byte2;
+
+    sample = q15_t(m_pack >> 12) - 2048;
+    break;
+  }
+  case 3:
+    sample = q15_t(m_pack & FM_UPSAMPLE_MASK) - 2048;
+  break;
+  default:
+    sample = 0;
+  break;
+  }
+
+  m_upSampleIndex++;
+  if(m_upSampleIndex >= 6U)
+    m_upSampleIndex = 0U;
+
+  return true;
+}
+
+uint16_t CFMUpSampler::getSpace() const
+{
+  //return available space in bytes
+  return m_samples.getSpace() * sizeof(TSamplePairPack);
+}
+
+#endif
+

FMUpSampler.h

@@ -0,0 +1,54 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include "Config.h"
+
+#if defined(MODE_FM)
+
+#if !defined(FMUPSAMPLER_H)
+#define FMUPSAMPLER_H
+
+#include "RingBuffer.h"
+#include "FMSamplePairPack.h"
+
+class CFMUpSampler {
+public:
+  CFMUpSampler();
+
+  void reset();
+
+  void addData(const uint8_t* data, uint16_t length);
+
+  bool getSample(q15_t& sample);
+
+  uint16_t getSpace() const;
+
+private:
+  uint8_t m_upSampleIndex;
+  uint32_t m_pack;
+  uint8_t * m_packPointer;
+  CRingBuffer<TSamplePairPack> m_samples;
+  bool m_running;
+};
+
+#endif
+
+#endif
+

Globals.h

@@ -28,6 +28,7 @@
 #include "STM32Utils.h"
 #else
 #include <Arduino.h>
+#undef PI //Undefine PI to get rid of annoying warning as it is also defined in arm_math.h.
 #endif
 
 #if defined(__SAM3X8E__) || defined(STM32F105xC)
@@ -50,7 +51,9 @@ enum MMDVM_STATE {
   STATE_P25       = 4,
   STATE_NXDN      = 5,
   STATE_POCSAG    = 6,
+  STATE_M17       = 7,
   STATE_FM        = 10,
+  STATE_AX25      = 11,
 
   // Dummy states start at 90
   STATE_NXDNCAL1K = 91,
@@ -84,6 +87,8 @@ enum MMDVM_STATE {
 #include "YSFTX.h"
 #include "P25RX.h"
 #include "P25TX.h"
+#include "M17RX.h"
+#include "M17TX.h"
 #include "NXDNRX.h"
 #include "NXDNTX.h"
 #include "POCSAGTX.h"
@@ -96,6 +101,8 @@ enum MMDVM_STATE {
 #include "CalPOCSAG.h"
 #include "CalRSSI.h"
 #include "CWIdTX.h"
+#include "AX25RX.h"
+#include "AX25TX.h"
 #include "Debug.h"
 #include "IO.h"
 #include "FM.h"
@@ -123,7 +130,9 @@ extern bool m_ysfEnable;
 extern bool m_p25Enable;
 extern bool m_nxdnEnable;
 extern bool m_pocsagEnable;
+extern bool m_m17Enable;
 extern bool m_fmEnable;
+extern bool m_ax25Enable;
 
 extern bool m_duplex;
 
@@ -133,9 +142,15 @@ extern bool m_dcd;
 extern CSerialPort serial;
 extern CIO io;
 
+#if defined(MODE_DSTAR)
 extern CDStarRX dstarRX;
 extern CDStarTX dstarTX;
 
+extern CCalDStarRX calDStarRX;
+extern CCalDStarTX calDStarTX;
+#endif
+
+#if defined(MODE_DMR)
 extern CDMRIdleRX dmrIdleRX;
 extern CDMRRX dmrRX;
 extern CDMRTX dmrTX;
@@ -143,28 +158,51 @@ extern CDMRTX dmrTX;
 extern CDMRDMORX dmrDMORX;
 extern CDMRDMOTX dmrDMOTX;
 
+extern CCalDMR calDMR;
+#endif
+
+#if defined(MODE_YSF)
 extern CYSFRX ysfRX;
 extern CYSFTX ysfTX;
+#endif
 
+#if defined(MODE_P25)
 extern CP25RX p25RX;
 extern CP25TX p25TX;
 
+extern CCalP25 calP25;
+#endif
+
+#if defined(MODE_NXDN)
 extern CNXDNRX nxdnRX;
 extern CNXDNTX nxdnTX;
 
-extern CPOCSAGTX pocsagTX;
+extern CCalNXDN calNXDN;
+#endif
 
-extern CFM fm;
+#if defined(MODE_POCSAG)
+extern CPOCSAGTX  pocsagTX;
+extern CCalPOCSAG calPOCSAG;
+#endif
 
-extern CCalDStarRX calDStarRX;
-extern CCalDStarTX calDStarTX;
-extern CCalDMR     calDMR;
-extern CCalFM      calFM;
-extern CCalP25     calP25;
-extern CCalNXDN    calNXDN;
-extern CCalPOCSAG  calPOCSAG;
-extern CCalRSSI    calRSSI;
+#if defined(MODE_M17)
+extern CM17RX m17RX;
+extern CM17TX m17TX;
+#endif
+
+#if defined(MODE_FM)
+extern CFM    fm;
+extern CCalFM calFM;
+#endif
+
+#if defined(MODE_AX25)
+extern CAX25RX ax25RX;
+extern CAX25TX ax25TX;
+#endif
+
+extern CCalRSSI calRSSI;
 
 extern CCWIdTX cwIdTX;
 
 #endif
+

IO.cpp

@@ -22,16 +22,34 @@
 #include "Globals.h"
 #include "IO.h"
 
+#if defined(USE_DCBLOCKER)
 // Generated using [b, a] = butter(1, 0.001) in MATLAB
 static q31_t   DC_FILTER[] = {3367972, 0, 3367972, 0, 2140747704, 0}; // {b0, 0, b1, b2, -a1, -a2}
 const uint32_t DC_FILTER_STAGES = 1U; // One Biquad stage
+#endif
 
+#if defined(MODE_DMR) || defined(MODE_YSF)
 // Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
 static q15_t RRC_0_2_FILTER[] = {401, 104, -340, -731, -847, -553, 112, 909, 1472, 1450, 683, -675, -2144, -3040, -2706, -770, 2667, 6995,
                                  11237, 14331, 15464, 14331, 11237, 6995, 2667, -770, -2706, -3040, -2144, -675, 683, 1450, 1472, 909, 112,
                                  -553, -847, -731, -340, 104, 401, 0};
 const uint16_t RRC_0_2_FILTER_LEN = 42U;
+#endif
 
+#if defined(MODE_M17)
+// Generated using rcosdesign(0.5, 8, 5, 'sqrt') in MATLAB
+static q15_t RRC_0_5_FILTER[] = {-147, -88, 72, 220, 223, 46, -197, -285, -79, 334, 623, 390, -498, -1691, -2363, -1556, 1284, 5872, 11033,
+				  15109, 16656, 15109, 11033, 5872, 1284, -1556, -2363, -1691, -498, 390, 623, 334, -79, -285, -197, 46, 223,
+				  220, 72, -88, -147, 0};
+const uint16_t RRC_0_5_FILTER_LEN = 42U;
+#endif
+
+#if defined(MODE_NXDN)
+#if defined(USE_NXDN_BOXCAR)
+// One symbol boxcar filter
+static q15_t   BOXCAR10_FILTER[] = {6000, 6000, 6000, 6000, 6000, 6000, 6000, 6000, 6000, 6000};
+const uint16_t BOXCAR10_FILTER_LEN = 10U;
+#else
 // Generated using rcosdesign(0.2, 8, 10, 'sqrt') in MATLAB
 static q15_t NXDN_0_2_FILTER[] = {284, 198, 73, -78, -240, -393, -517, -590, -599, -533, -391, -181, 79, 364, 643, 880, 1041, 1097, 1026, 819,
                                   483, 39, -477, -1016, -1516, -1915, -2150, -2164, -1914, -1375, -545, 557, 1886, 3376, 4946, 6502, 7946, 9184,
@@ -43,14 +61,20 @@ const uint16_t NXDN_0_2_FILTER_LEN = 82U;
 static q15_t NXDN_ISINC_FILTER[] = {790, -1085, -1073, -553, 747, 2341, 3156, 2152, -893, -4915, -7834, -7536, -3102, 4441, 12354, 17394, 17394,
                                    12354, 4441, -3102, -7536, -7834, -4915, -893, 2152, 3156, 2341, 747, -553, -1073, -1085, 790};
 const uint16_t NXDN_ISINC_FILTER_LEN = 32U;
+#endif
+#endif
 
+#if defined(MODE_DSTAR)
 // Generated using gaussfir(0.5, 4, 5) in MATLAB
 static q15_t   GAUSSIAN_0_5_FILTER[] = {8, 104, 760, 3158, 7421, 9866, 7421, 3158, 760, 104, 8, 0};
 const uint16_t GAUSSIAN_0_5_FILTER_LEN = 12U;
+#endif
 
+#if defined(MODE_P25)
 // One symbol boxcar filter
-static q15_t   BOXCAR_FILTER[] = {12000, 12000, 12000, 12000, 12000, 0};
-const uint16_t BOXCAR_FILTER_LEN = 6U;
+static q15_t   BOXCAR5_FILTER[] = {12000, 12000, 12000, 12000, 12000, 0};
+const uint16_t BOXCAR5_FILTER_LEN = 6U;
+#endif
 
 const uint16_t DC_OFFSET = 2048U;
 
@@ -59,18 +83,37 @@ m_started(false),
 m_rxBuffer(RX_RINGBUFFER_SIZE),
 m_txBuffer(TX_RINGBUFFER_SIZE),
 m_rssiBuffer(RX_RINGBUFFER_SIZE),
+#if defined(USE_DCBLOCKER)
 m_dcFilter(),
 m_dcState(),
-m_rrcFilter(),
+#endif
+#if defined(MODE_DSTAR)
 m_gaussianFilter(),
-m_boxcarFilter(),
+m_gaussianState(),
+#endif
+#if defined(MODE_DMR) || defined(MODE_YSF)
+m_rrc02Filter(),
+m_rrc02State(),
+#endif
+#if defined(MODE_P25)
+m_boxcar5Filter(),
+m_boxcar5State(),
+#endif
+#if defined(MODE_NXDN)
+#if defined(USE_NXDN_BOXCAR)
+m_boxcar10Filter(),
+m_boxcar10State(),
+#else
 m_nxdnFilter(),
 m_nxdnISincFilter(),
-m_rrcState(),
-m_gaussianState(),
-m_boxcarState(),
 m_nxdnState(),
 m_nxdnISincState(),
+#endif
+#endif
+#if defined(MODE_M17)
+m_rrc05Filter(),
+m_rrc05State(),
+#endif
 m_pttInvert(false),
 m_rxLevel(128 * 128),
 m_cwIdTXLevel(128 * 128),
@@ -79,10 +122,13 @@ m_dmrTXLevel(128 * 128),
 m_ysfTXLevel(128 * 128),
 m_p25TXLevel(128 * 128),
 m_nxdnTXLevel(128 * 128),
+m_m17TXLevel(128 * 128),
 m_pocsagTXLevel(128 * 128),
 m_fmTXLevel(128 * 128),
+m_ax25TXLevel(128 * 128),
 m_rxDCOffset(DC_OFFSET),
 m_txDCOffset(DC_OFFSET),
+m_useCOSAsLockout(false),
 m_ledCount(0U),
 m_ledValue(true),
 m_detect(false),
@@ -91,30 +137,45 @@ m_dacOverflow(0U),
 m_watchdog(0U),
 m_lockout(false)
 {
-  ::memset(m_rrcState,      0x00U,  70U * sizeof(q15_t));
-  ::memset(m_gaussianState, 0x00U,  40U * sizeof(q15_t));
-  ::memset(m_boxcarState,   0x00U,  30U * sizeof(q15_t));
-  ::memset(m_nxdnState,     0x00U, 110U * sizeof(q15_t));
-  ::memset(m_nxdnISincState, 0x00U, 60U * sizeof(q15_t));
+#if defined(USE_DCBLOCKER)
   ::memset(m_dcState,       0x00U,   4U * sizeof(q31_t));
-
   m_dcFilter.numStages = DC_FILTER_STAGES;
   m_dcFilter.pState    = m_dcState;
   m_dcFilter.pCoeffs   = DC_FILTER;
   m_dcFilter.postShift = 0;
+#endif
 
-  m_rrcFilter.numTaps = RRC_0_2_FILTER_LEN;
-  m_rrcFilter.pState  = m_rrcState;
-  m_rrcFilter.pCoeffs = RRC_0_2_FILTER;
-
+#if defined(MODE_DSTAR)
+  ::memset(m_gaussianState, 0x00U, 40U * sizeof(q15_t));
   m_gaussianFilter.numTaps = GAUSSIAN_0_5_FILTER_LEN;
   m_gaussianFilter.pState  = m_gaussianState;
   m_gaussianFilter.pCoeffs = GAUSSIAN_0_5_FILTER;
+#endif
+
+#if defined(MODE_DMR) || defined(MODE_YSF)
+  ::memset(m_rrc02State, 0x00U, 70U * sizeof(q15_t));
+  m_rrc02Filter.numTaps = RRC_0_2_FILTER_LEN;
+  m_rrc02Filter.pState  = m_rrc02State;
+  m_rrc02Filter.pCoeffs = RRC_0_2_FILTER;
+#endif
+
+#if defined(MODE_P25)
+  ::memset(m_boxcar5State, 0x00U, 30U * sizeof(q15_t));
+  m_boxcar5Filter.numTaps = BOXCAR5_FILTER_LEN;
+  m_boxcar5Filter.pState  = m_boxcar5State;
+  m_boxcar5Filter.pCoeffs = BOXCAR5_FILTER;
+#endif
+
+#if defined(MODE_NXDN)
+#if defined(USE_NXDN_BOXCAR)
+  ::memset(m_boxcar10State, 0x00U, 40U * sizeof(q15_t));
+  m_boxcar10Filter.numTaps = BOXCAR10_FILTER_LEN;
+  m_boxcar10Filter.pState  = m_boxcar10State;
+  m_boxcar10Filter.pCoeffs = BOXCAR10_FILTER;
+#else
+  ::memset(m_nxdnState,      0x00U, 110U * sizeof(q15_t));
+  ::memset(m_nxdnISincState, 0x00U, 60U * sizeof(q15_t));
 
-  m_boxcarFilter.numTaps = BOXCAR_FILTER_LEN;
-  m_boxcarFilter.pState  = m_boxcarState;
-  m_boxcarFilter.pCoeffs = BOXCAR_FILTER;
-  
   m_nxdnFilter.numTaps = NXDN_0_2_FILTER_LEN;
   m_nxdnFilter.pState  = m_nxdnState;
   m_nxdnFilter.pCoeffs = NXDN_0_2_FILTER;
@@ -122,6 +183,15 @@ m_lockout(false)
   m_nxdnISincFilter.numTaps = NXDN_ISINC_FILTER_LEN;
   m_nxdnISincFilter.pState  = m_nxdnISincState;
   m_nxdnISincFilter.pCoeffs = NXDN_ISINC_FILTER;
+#endif
+#endif
+
+#if defined(MODE_M17)
+  ::memset(m_rrc05State, 0x00U, 70U * sizeof(q15_t));
+  m_rrc05Filter.numTaps = RRC_0_5_FILTER_LEN;
+  m_rrc05Filter.pState  = m_rrc05State;
+  m_rrc05Filter.pCoeffs = RRC_0_5_FILTER;
+#endif
 
   initInt();
   
@@ -132,7 +202,7 @@ void CIO::selfTest()
 {
   bool ledValue = false;
 
-  for (uint8_t i = 0; i < 6; i++) {
+  for (uint8_t i = 0U; i < 6U; i++) {
     ledValue = !ledValue;
 
     // We exclude PTT to avoid trigger the transmitter
@@ -143,21 +213,40 @@ void CIO::selfTest()
     setDMRInt(ledValue);
     setYSFInt(ledValue);
     setP25Int(ledValue);
+#if !defined(USE_ALTERNATE_NXDN_LEDS)
     setNXDNInt(ledValue);
+#endif
+#if !defined(USE_ALTERNATE_M17_LEDS)
+    setM17Int(ledValue);
+#endif
+#if !defined(USE_ALTERNATE_POCSAG_LEDS)
     setPOCSAGInt(ledValue);
+#endif
+#if !defined(USE_ALTERNATE_FM_LEDS)
     setFMInt(ledValue);
+#endif
 #endif
     delayInt(250);
   }
 
 #if defined(MODE_LEDS)
-  setDStarInt(true);
+  setDStarInt(false);
   setDMRInt(false);
   setYSFInt(false);
   setP25Int(false);
+#if !defined(USE_ALTERNATE_NXDN_LEDS)
   setNXDNInt(false);
+#endif
+#if !defined(USE_ALTERNATE_M17_LEDS)
+  setM17Int(false);
+#endif
+#if !defined(USE_ALTERNATE_POCSAG_LEDS)
   setPOCSAGInt(false);
+#endif
+#if !defined(USE_ALTERNATE_FM_LEDS)
   setFMInt(false);
+#endif
+  setDStarInt(true);
 
   delayInt(250);
   setDMRInt(true);
@@ -173,6 +262,11 @@ void CIO::selfTest()
   setNXDNInt(true);
 #endif
 
+#if !defined(USE_ALTERNATE_M17_LEDS)
+  delayInt(250);
+  setM17Int(true);
+#endif
+
 #if !defined(USE_ALTERNATE_POCSAG_LEDS)
   delayInt(250);
   setPOCSAGInt(true);
@@ -191,6 +285,11 @@ void CIO::selfTest()
   setPOCSAGInt(false);
 #endif
 
+#if !defined(USE_ALTERNATE_M17_LEDS)
+  delayInt(250);
+  setM17Int(false);
+#endif
+
 #if !defined(USE_ALTERNATE_NXDN_LEDS)
   delayInt(250);
   setNXDNInt(false);
@@ -219,7 +318,7 @@ void CIO::start()
 
   m_started = true;
 
-  setMode();
+  setMode(STATE_IDLE);
 }
 
 void CIO::process()
@@ -228,11 +327,12 @@ void CIO::process()
   if (m_started) {
     // Two seconds timeout
     if (m_watchdog >= 48000U) {
-      if (m_modemState == STATE_DSTAR || m_modemState == STATE_DMR || m_modemState == STATE_YSF || m_modemState == STATE_P25 || m_modemState == STATE_NXDN || m_modemState == STATE_POCSAG) {
+      if (m_modemState == STATE_DSTAR || m_modemState == STATE_DMR || m_modemState == STATE_YSF || m_modemState == STATE_P25 || m_modemState == STATE_NXDN || m_modemState == STATE_M17 || m_modemState == STATE_POCSAG) {
+#if defined(MODE_DMR)
         if (m_modemState == STATE_DMR && m_tx)
           dmrTX.setStart(false);
-        m_modemState = STATE_IDLE;
-        setMode();
+#endif
+        setMode(STATE_IDLE);
       }
 
       m_watchdog = 0U;
@@ -256,14 +356,14 @@ void CIO::process()
     return;
   }
 
-#if defined(USE_COS_AS_LOCKOUT)
-  m_lockout = getCOSInt();
-#endif
+  if (m_useCOSAsLockout)
+    m_lockout = getCOSInt();
 
   // Switch off the transmitter if needed
   if (m_txBuffer.getData() == 0U && m_tx) {
     m_tx = false;
     setPTTInt(m_pttInvert ? true : false);
+    DEBUG1("TX OFF");
   }
 
   if (m_rxBuffer.getData() >= RX_BLOCK_SIZE) {
@@ -272,15 +372,16 @@ void CIO::process()
     uint16_t rssi[RX_BLOCK_SIZE];
 
     for (uint16_t i = 0U; i < RX_BLOCK_SIZE; i++) {
-      uint16_t sample;
-      m_rxBuffer.get(sample, control[i]);
+      TSample sample;
+      m_rxBuffer.get(sample);
+      control[i] = sample.control;
       m_rssiBuffer.get(rssi[i]);
 
       // Detect ADC overflow
-      if (m_detect && (sample == 0U || sample == 4095U))
+      if (m_detect && (sample.sample == 0U || sample.sample == 4095U))
         m_adcOverflow++;
 
-      q15_t res1 = q15_t(sample) - m_rxDCOffset;
+      q15_t res1 = q15_t(sample.sample) - m_rxDCOffset;
       q31_t res2 = res1 * m_rxLevel;
       samples[i] = q15_t(__SSAT((res2 >> 15), 16));
     }
@@ -308,6 +409,7 @@ void CIO::process()
 #endif
 
     if (m_modemState == STATE_IDLE) {
+#if defined(MODE_DSTAR)
       if (m_dstarEnable) {
         q15_t GMSKVals[RX_BLOCK_SIZE];
 #if defined(USE_DCBLOCKER)
@@ -317,45 +419,79 @@ void CIO::process()
 #endif
         dstarRX.samples(GMSKVals, rssi, RX_BLOCK_SIZE);
       }
+#endif
 
+#if defined(MODE_P25)
       if (m_p25Enable) {
         q15_t P25Vals[RX_BLOCK_SIZE];
 #if defined(USE_DCBLOCKER)
-        ::arm_fir_fast_q15(&m_boxcarFilter, dcSamples, P25Vals, RX_BLOCK_SIZE);
+        ::arm_fir_fast_q15(&m_boxcar5Filter, dcSamples, P25Vals, RX_BLOCK_SIZE);
 #else
-        ::arm_fir_fast_q15(&m_boxcarFilter, samples, P25Vals, RX_BLOCK_SIZE);
+        ::arm_fir_fast_q15(&m_boxcar5Filter, samples, P25Vals, RX_BLOCK_SIZE);
 #endif
         p25RX.samples(P25Vals, rssi, RX_BLOCK_SIZE);
       }
+#endif
 
+#if defined(MODE_NXDN)
       if (m_nxdnEnable) {
+        q15_t NXDNVals[RX_BLOCK_SIZE];
+#if defined(USE_NXDN_BOXCAR)
+#if defined(USE_DCBLOCKER)
+        ::arm_fir_fast_q15(&m_boxcar10Filter, dcSamples, NXDNVals, RX_BLOCK_SIZE);
+#else
+        ::arm_fir_fast_q15(&m_boxcar10Filter, samples, NXDNVals, RX_BLOCK_SIZE);
+#endif
+#else
         q15_t NXDNValsTmp[RX_BLOCK_SIZE];
 #if defined(USE_DCBLOCKER)
         ::arm_fir_fast_q15(&m_nxdnFilter, dcSamples, NXDNValsTmp, RX_BLOCK_SIZE);
 #else
         ::arm_fir_fast_q15(&m_nxdnFilter, samples, NXDNValsTmp, RX_BLOCK_SIZE);
 #endif
-        q15_t NXDNVals[RX_BLOCK_SIZE];
         ::arm_fir_fast_q15(&m_nxdnISincFilter, NXDNValsTmp, NXDNVals, RX_BLOCK_SIZE);
-
+#endif
         nxdnRX.samples(NXDNVals, rssi, RX_BLOCK_SIZE);
       }
+#endif
 
-      if (m_dmrEnable || m_ysfEnable) {
-        q15_t RRCVals[RX_BLOCK_SIZE];
-        ::arm_fir_fast_q15(&m_rrcFilter, samples, RRCVals, RX_BLOCK_SIZE);
+#if defined(MODE_DMR)
+      if (m_dmrEnable) {
+        q15_t DMRVals[RX_BLOCK_SIZE];
+        ::arm_fir_fast_q15(&m_rrc02Filter, samples, DMRVals, RX_BLOCK_SIZE);
 
-        if (m_ysfEnable)
-          ysfRX.samples(RRCVals, rssi, RX_BLOCK_SIZE);
-
-        if (m_dmrEnable) {
-          if (m_duplex)
-            dmrIdleRX.samples(RRCVals, RX_BLOCK_SIZE);
-          else
-            dmrDMORX.samples(RRCVals, rssi, RX_BLOCK_SIZE);
-        }
+        if (m_duplex)
+          dmrIdleRX.samples(DMRVals, RX_BLOCK_SIZE);
+        else
+          dmrDMORX.samples(DMRVals, rssi, RX_BLOCK_SIZE);
       }
+#endif
 
+#if defined(MODE_YSF)
+      if (m_ysfEnable) {
+        q15_t YSFVals[RX_BLOCK_SIZE];
+#if defined(USE_DCBLOCKER)
+        ::arm_fir_fast_q15(&m_rrc02Filter, dcSamples, YSFVals, RX_BLOCK_SIZE);
+#else
+        ::arm_fir_fast_q15(&m_rrc02Filter, samples, YSFVals, RX_BLOCK_SIZE);
+#endif
+        ysfRX.samples(YSFVals, rssi, RX_BLOCK_SIZE);
+      }
+#endif
+
+#if defined(MODE_M17)
+      if (m_m17Enable) {
+        q15_t RRCVals[RX_BLOCK_SIZE];
+#if defined(USE_DCBLOCKER)
+        ::arm_fir_fast_q15(&m_rrc05Filter, dcSamples, RRCVals, RX_BLOCK_SIZE);
+#else
+        ::arm_fir_fast_q15(&m_rrc05Filter, samples, RRCVals, RX_BLOCK_SIZE);
+#endif
+        m17RX.samples(RRCVals, rssi, RX_BLOCK_SIZE);
+      }
+#endif
+
+#if defined(MODE_FM)
       if (m_fmEnable) {
         bool cos = getCOSInt();
 #if defined(USE_DCBLOCKER)
@@ -364,7 +500,21 @@ void CIO::process()
         fm.samples(cos, samples, RX_BLOCK_SIZE);
 #endif
       }
-    } else if (m_modemState == STATE_DSTAR) {
+#endif
+
+#if defined(MODE_FM) && defined(MODE_AX25)
+      if (m_ax25Enable) {
+#if defined(USE_DCBLOCKER)
+        ax25RX.samples(dcSamples, RX_BLOCK_SIZE);
+#else
+        ax25RX.samples(samples, RX_BLOCK_SIZE);
+#endif
+      }
+#endif
+    }
+
+#if defined(MODE_DSTAR)
+    else if (m_modemState == STATE_DSTAR) {
       if (m_dstarEnable) {
         q15_t GMSKVals[RX_BLOCK_SIZE];
 #if defined(USE_DCBLOCKER)
@@ -374,10 +524,14 @@ void CIO::process()
 #endif
         dstarRX.samples(GMSKVals, rssi, RX_BLOCK_SIZE);
       }
-    } else if (m_modemState == STATE_DMR) {
+    }
+#endif
+
+#if defined(MODE_DMR)
+    else if (m_modemState == STATE_DMR) {
       if (m_dmrEnable) {
         q15_t DMRVals[RX_BLOCK_SIZE];
-        ::arm_fir_fast_q15(&m_rrcFilter, samples, DMRVals, RX_BLOCK_SIZE);
+        ::arm_fir_fast_q15(&m_rrc02Filter, samples, DMRVals, RX_BLOCK_SIZE);
 
         if (m_duplex) {
           // If the transmitter isn't on, use the DMR idle RX to detect the wakeup CSBKs
@@ -389,52 +543,106 @@ void CIO::process()
           dmrDMORX.samples(DMRVals, rssi, RX_BLOCK_SIZE);
         }
       }
-    } else if (m_modemState == STATE_YSF) {
+    }
+#endif
+
+#if defined(MODE_YSF)
+    else if (m_modemState == STATE_YSF) {
       if (m_ysfEnable) {
         q15_t YSFVals[RX_BLOCK_SIZE];
 #if defined(USE_DCBLOCKER)
-        ::arm_fir_fast_q15(&m_rrcFilter, dcSamples, YSFVals, RX_BLOCK_SIZE);
+        ::arm_fir_fast_q15(&m_rrc02Filter, dcSamples, YSFVals, RX_BLOCK_SIZE);
 #else
-        ::arm_fir_fast_q15(&m_rrcFilter, samples, YSFVals, RX_BLOCK_SIZE);
+        ::arm_fir_fast_q15(&m_rrc02Filter, samples, YSFVals, RX_BLOCK_SIZE);
 #endif
         ysfRX.samples(YSFVals, rssi, RX_BLOCK_SIZE);
       }
-    } else if (m_modemState == STATE_P25) {
+    }
+#endif
+
+#if defined(MODE_P25)
+    else if (m_modemState == STATE_P25) {
       if (m_p25Enable) {
         q15_t P25Vals[RX_BLOCK_SIZE];
 #if defined(USE_DCBLOCKER)
-        ::arm_fir_fast_q15(&m_boxcarFilter, dcSamples, P25Vals, RX_BLOCK_SIZE);
+        ::arm_fir_fast_q15(&m_boxcar5Filter, dcSamples, P25Vals, RX_BLOCK_SIZE);
 #else
-        ::arm_fir_fast_q15(&m_boxcarFilter, samples, P25Vals, RX_BLOCK_SIZE);
+        ::arm_fir_fast_q15(&m_boxcar5Filter, samples, P25Vals, RX_BLOCK_SIZE);
 #endif
         p25RX.samples(P25Vals, rssi, RX_BLOCK_SIZE);
       }
-    } else if (m_modemState == STATE_NXDN) {
+    }
+#endif
+
+#if defined(MODE_NXDN)
+    else if (m_modemState == STATE_NXDN) {
       if (m_nxdnEnable) {
+        q15_t NXDNVals[RX_BLOCK_SIZE];
+#if defined(USE_NXDN_BOXCAR)
+#if defined(USE_DCBLOCKER)
+        ::arm_fir_fast_q15(&m_boxcar10Filter, dcSamples, NXDNVals, RX_BLOCK_SIZE);
+#else
+        ::arm_fir_fast_q15(&m_boxcar10Filter, samples, NXDNVals, RX_BLOCK_SIZE);
+#endif
+#else
         q15_t NXDNValsTmp[RX_BLOCK_SIZE];
 #if defined(USE_DCBLOCKER)
         ::arm_fir_fast_q15(&m_nxdnFilter, dcSamples, NXDNValsTmp, RX_BLOCK_SIZE);
 #else
         ::arm_fir_fast_q15(&m_nxdnFilter, samples, NXDNValsTmp, RX_BLOCK_SIZE);
 #endif
-        q15_t NXDNVals[RX_BLOCK_SIZE];
         ::arm_fir_fast_q15(&m_nxdnISincFilter, NXDNValsTmp, NXDNVals, RX_BLOCK_SIZE);
-
+#endif
         nxdnRX.samples(NXDNVals, rssi, RX_BLOCK_SIZE);
       }
-    } else if (m_modemState == STATE_FM) {
+    }
+#endif
+
+#if defined(MODE_M17)
+    else if (m_modemState == STATE_M17) {
+      if (m_m17Enable) {
+        q15_t M17Vals[RX_BLOCK_SIZE];
+#if defined(USE_DCBLOCKER)
+        ::arm_fir_fast_q15(&m_rrc05Filter, dcSamples, M17Vals, RX_BLOCK_SIZE);
+#else
+        ::arm_fir_fast_q15(&m_rrc05Filter, samples, M17Vals, RX_BLOCK_SIZE);
+#endif
+        m17RX.samples(M17Vals, rssi, RX_BLOCK_SIZE);
+      }
+    }
+#endif
+
+#if defined(MODE_FM)
+    else if (m_modemState == STATE_FM) {
       bool cos = getCOSInt();
 #if defined(USE_DCBLOCKER)
       fm.samples(cos, dcSamples, RX_BLOCK_SIZE);
+
+#if defined(MODE_AX25)
+      if (m_ax25Enable)
+        ax25RX.samples(dcSamples, RX_BLOCK_SIZE);
+#endif
 #else
       fm.samples(cos, samples, RX_BLOCK_SIZE);
+
+#if defined(MODE_AX25)
+      if (m_ax25Enable)
+        ax25RX.samples(samples, RX_BLOCK_SIZE);
 #endif
-    } else if (m_modemState == STATE_DSTARCAL) {
+#endif
+    }
+#endif
+
+#if defined(MODE_DSTAR)
+    else if (m_modemState == STATE_DSTARCAL) {
       q15_t GMSKVals[RX_BLOCK_SIZE];
       ::arm_fir_fast_q15(&m_gaussianFilter, samples, GMSKVals, RX_BLOCK_SIZE);
 
       calDStarRX.samples(GMSKVals, RX_BLOCK_SIZE);
-    } else if (m_modemState == STATE_RSSICAL) {
+    }
+#endif
+
+    else if (m_modemState == STATE_RSSICAL) {
       calRSSI.samples(rssi, RX_BLOCK_SIZE);
     }
   }
@@ -452,6 +660,7 @@ void CIO::write(MMDVM_STATE mode, q15_t* samples, uint16_t length, const uint8_t
   if (!m_tx) {
     m_tx = true;
     setPTTInt(m_pttInvert ? false : true);
+    DEBUG1("TX ON");
   }
 
   q15_t txLevel = 0;
@@ -471,12 +680,18 @@ void CIO::write(MMDVM_STATE mode, q15_t* samples, uint16_t length, const uint8_t
     case STATE_NXDN:
       txLevel = m_nxdnTXLevel;
       break;
+    case STATE_M17:
+      txLevel = m_m17TXLevel;
+      break;
     case STATE_POCSAG:
       txLevel = m_pocsagTXLevel;
       break;
     case STATE_FM:
       txLevel = m_fmTXLevel;
       break;
+    case STATE_AX25:
+      txLevel = m_ax25TXLevel;
+      break;
     default:
       txLevel = m_cwIdTXLevel;
       break;
@@ -492,9 +707,9 @@ void CIO::write(MMDVM_STATE mode, q15_t* samples, uint16_t length, const uint8_t
       m_dacOverflow++;
 
     if (control == NULL)
-      m_txBuffer.put(res3, MARK_NONE);
+      m_txBuffer.put({res3, MARK_NONE});
     else
-      m_txBuffer.put(res3, control[i]);
+      m_txBuffer.put({res3, control[i]});
   }
 }
 
@@ -516,20 +731,41 @@ void CIO::setADCDetection(bool detect)
   m_detect = detect;
 }
 
-void CIO::setMode()
+void CIO::setMode(MMDVM_STATE state)
 {
+  if (state == m_modemState)
+    return;
+
 #if defined(MODE_LEDS)
-  setDStarInt(m_modemState == STATE_DSTAR);
-  setDMRInt(m_modemState   == STATE_DMR);
-  setYSFInt(m_modemState   == STATE_YSF);
-  setP25Int(m_modemState   == STATE_P25);
-  setNXDNInt(m_modemState  == STATE_NXDN);
-  setPOCSAGInt(m_modemState  == STATE_POCSAG);
-  setFMInt(m_modemState == STATE_FM);
+  switch (m_modemState) {
+    case STATE_DSTAR:  setDStarInt(false);  break;
+    case STATE_DMR:    setDMRInt(false);    break;
+    case STATE_YSF:    setYSFInt(false);    break;
+    case STATE_P25:    setP25Int(false);    break;
+    case STATE_NXDN:   setNXDNInt(false);   break;
+    case STATE_M17:    setM17Int(false);    break;
+    case STATE_POCSAG: setPOCSAGInt(false); break;
+    case STATE_FM:     setFMInt(false);     break;
+    default: break;
+  }
+
+  switch (state) {
+    case STATE_DSTAR:  setDStarInt(true);  break;
+    case STATE_DMR:    setDMRInt(true);    break;
+    case STATE_YSF:    setYSFInt(true);    break;
+    case STATE_P25:    setP25Int(true);    break;
+    case STATE_NXDN:   setNXDNInt(true);   break;
+    case STATE_M17:    setM17Int(true);    break;
+    case STATE_POCSAG: setPOCSAGInt(true); break;
+    case STATE_FM:     setFMInt(true);     break;
+    default: break;
+  }
 #endif
+
+  m_modemState = state;
 }
 
-void CIO::setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rxLevel, uint8_t cwIdTXLevel, uint8_t dstarTXLevel, uint8_t dmrTXLevel, uint8_t ysfTXLevel, uint8_t p25TXLevel, uint8_t nxdnTXLevel, uint8_t pocsagTXLevel, uint8_t fmTXLevel, int16_t txDCOffset, int16_t rxDCOffset)
+void CIO::setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rxLevel, uint8_t cwIdTXLevel, uint8_t dstarTXLevel, uint8_t dmrTXLevel, uint8_t ysfTXLevel, uint8_t p25TXLevel, uint8_t nxdnTXLevel, uint8_t m17TXLevel, uint8_t pocsagTXLevel, uint8_t fmTXLevel, uint8_t ax25TXLevel, int16_t txDCOffset, int16_t rxDCOffset, bool useCOSAsLockout)
 {
   m_pttInvert = pttInvert;
 
@@ -540,11 +776,15 @@ void CIO::setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rx
   m_ysfTXLevel    = q15_t(ysfTXLevel * 128);
   m_p25TXLevel    = q15_t(p25TXLevel * 128);
   m_nxdnTXLevel   = q15_t(nxdnTXLevel * 128);
+  m_m17TXLevel    = q15_t(m17TXLevel * 128);
   m_pocsagTXLevel = q15_t(pocsagTXLevel * 128);
   m_fmTXLevel     = q15_t(fmTXLevel * 128);
+  m_ax25TXLevel   = q15_t(ax25TXLevel * 128);
 
   m_rxDCOffset   = DC_OFFSET + rxDCOffset;
   m_txDCOffset   = DC_OFFSET + txDCOffset;
+
+  m_useCOSAsLockout = useCOSAsLockout;
   
   if (rxInvert)
     m_rxLevel = -m_rxLevel;
@@ -555,6 +795,7 @@ void CIO::setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rx
     m_ysfTXLevel    = -m_ysfTXLevel;
     m_p25TXLevel    = -m_p25TXLevel;
     m_nxdnTXLevel   = -m_nxdnTXLevel;
+    m_m17TXLevel    = -m_m17TXLevel;
     m_pocsagTXLevel = -m_pocsagTXLevel;
   }
 }

IO.h

@@ -21,8 +21,12 @@
 
 #include "Globals.h"
 
-#include "SampleRB.h"
-#include "RSSIRB.h"
+#include "RingBuffer.h"
+
+struct TSample {
+  volatile uint16_t sample;
+  volatile uint8_t control;
+};
 
 class CIO {
 public:
@@ -38,11 +42,11 @@ public:
 
   void setDecode(bool dcd);
   void setADCDetection(bool detect);
-  void setMode();
+  void setMode(MMDVM_STATE state);
   
   void interrupt();
 
-  void setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rxLevel, uint8_t cwIdTXLevel, uint8_t dstarTXLevel, uint8_t dmrTXLevel, uint8_t ysfTXLevel, uint8_t p25TXLevel, uint8_t nxdnTXLevel, uint8_t pocsagTXLevel, uint8_t fmTXLevel, int16_t txDCOffset, int16_t rxDCOffset);
+  void setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rxLevel, uint8_t cwIdTXLevel, uint8_t dstarTXLevel, uint8_t dmrTXLevel, uint8_t ysfTXLevel, uint8_t p25TXLevel, uint8_t nxdnTXLevel, uint8_t m17TXLevel, uint8_t pocsagTXLevel, uint8_t fmTXLevel, uint8_t ax25TXLevel, int16_t txDCOffset, int16_t rxDCOffset, bool useCOSAsLockout);
 
   void getOverflow(bool& adcOverflow, bool& dacOverflow);
 
@@ -54,28 +58,55 @@ public:
   void resetWatchdog();
   uint32_t getWatchdog();
   
+  uint8_t getCPU() const;
+
+  void getUDID(uint8_t* buffer);
+
   void selfTest();
 
 private:
-  bool                 m_started;
+  bool                  m_started;
 
-  CSampleRB            m_rxBuffer;
-  CSampleRB            m_txBuffer;
-  CRSSIRB              m_rssiBuffer;
+  CRingBuffer<TSample>  m_rxBuffer;
+  CRingBuffer<TSample>  m_txBuffer;
+  CRingBuffer<uint16_t> m_rssiBuffer;
 
+#if defined(USE_DCBLOCKER)
   arm_biquad_casd_df1_inst_q31 m_dcFilter;
   q31_t                        m_dcState[4];
+#endif
 
-  arm_fir_instance_q15 m_rrcFilter;
+#if defined(MODE_DSTAR)
   arm_fir_instance_q15 m_gaussianFilter;
-  arm_fir_instance_q15 m_boxcarFilter;
+  q15_t                m_gaussianState[40U];      // NoTaps + BlockSize - 1, 12 + 20 - 1 plus some spare
+#endif
+
+#if defined(MODE_DMR) || defined(MODE_YSF)
+  arm_fir_instance_q15 m_rrc02Filter;
+  q15_t                m_rrc02State[70U];         // NoTaps + BlockSize - 1, 42 + 20 - 1 plus some spare
+#endif
+
+#if defined(MODE_P25)
+  arm_fir_instance_q15 m_boxcar5Filter;
+  q15_t                m_boxcar5State[30U];        // NoTaps + BlockSize - 1,  6 + 20 - 1 plus some spare
+#endif
+
+#if defined(MODE_NXDN)
+#if defined(USE_NXDN_BOXCAR)
+  arm_fir_instance_q15 m_boxcar10Filter;
+  q15_t                m_boxcar10State[40U];      // NoTaps + BlockSize - 1, 10 + 20 - 1 plus some spare
+#else
   arm_fir_instance_q15 m_nxdnFilter;
   arm_fir_instance_q15 m_nxdnISincFilter;
-  q15_t                m_rrcState[70U];           // NoTaps + BlockSize - 1, 42 + 20 - 1 plus some spare
-  q15_t                m_gaussianState[40U];      // NoTaps + BlockSize - 1, 12 + 20 - 1 plus some spare
-  q15_t                m_boxcarState[30U];        // NoTaps + BlockSize - 1, 6 + 20 - 1 plus some spare
   q15_t                m_nxdnState[110U];         // NoTaps + BlockSize - 1, 82 + 20 - 1 plus some spare
   q15_t                m_nxdnISincState[60U];     // NoTaps + BlockSize - 1, 32 + 20 - 1 plus some spare
+#endif
+#endif
+
+#if defined(MODE_M17)
+  arm_fir_instance_q15 m_rrc05Filter;
+  q15_t                m_rrc05State[70U];         // NoTaps + BlockSize - 1, 42 + 20 - 1 plus some spare
+#endif
 
   bool                 m_pttInvert;
   q15_t                m_rxLevel;
@@ -85,12 +116,16 @@ private:
   q15_t                m_ysfTXLevel;
   q15_t                m_p25TXLevel;
   q15_t                m_nxdnTXLevel;
+  q15_t                m_m17TXLevel;
   q15_t                m_pocsagTXLevel;
   q15_t                m_fmTXLevel;
+  q15_t                m_ax25TXLevel;
 
   uint16_t             m_rxDCOffset;
   uint16_t             m_txDCOffset;
 
+  bool                 m_useCOSAsLockout;
+
   uint32_t             m_ledCount;
   bool                 m_ledValue;
 
@@ -119,6 +154,7 @@ private:
   void setP25Int(bool on);
   void setNXDNInt(bool on);
   void setPOCSAGInt(bool on);
+  void setM17Int(bool on);
   void setFMInt(bool on);
   
   void delayInt(unsigned int dly);

IODue.cpp

@@ -107,6 +107,9 @@ void CIO::initInt()
 #if !defined(USE_ALTERNATE_NXDN_LEDS)
   pinMode(PIN_NXDN,   OUTPUT);
 #endif
+#if !defined(USE_ALTERNATE_M17_LEDS)
+  pinMode(PIN_M17,    OUTPUT);
+#endif
 #if !defined(USE_ALTERNATE_POCSAG_LEDS)
   pinMode(PIN_POCSAG, OUTPUT);
 #endif
@@ -185,14 +188,13 @@ void CIO::startInt()
 void CIO::interrupt()
 {
   if ((ADC->ADC_ISR & ADC_ISR_EOC_Chan) == ADC_ISR_EOC_Chan) {    // Ensure there was an End-of-Conversion and we read the ISR reg
-    uint8_t control = MARK_NONE;
-    uint16_t sample = DC_OFFSET;
+    TSample sample = {DC_OFFSET, MARK_NONE};
 
-    m_txBuffer.get(sample, control);
-    DACC->DACC_CDR = sample;
+    m_txBuffer.get(sample);
+    DACC->DACC_CDR = sample.sample;
 
-    sample = ADC->ADC_CDR[ADC_CDR_Chan];
-    m_rxBuffer.put(sample, control);
+    sample.sample = ADC->ADC_CDR[ADC_CDR_Chan];
+    m_rxBuffer.put(sample);
 
 #if defined(SEND_RSSI_DATA)
     m_rssiBuffer.put(ADC->ADC_CDR[RSSI_CDR_Chan]);
@@ -254,6 +256,16 @@ void CIO::setNXDNInt(bool on)
 #endif
 }
 
+void CIO::setM17Int(bool on)
+{
+#if defined(USE_ALTERNATE_M17_LEDS)
+  digitalWrite(PIN_DSTAR, on ? HIGH : LOW);
+  digitalWrite(PIN_P25,   on ? HIGH : LOW);
+#else
+  digitalWrite(PIN_M17, on ? HIGH : LOW);
+#endif
+}
+
 void CIO::setPOCSAGInt(bool on)
 {
 #if defined(USE_ALTERNATE_POCSAG_LEDS)
@@ -279,4 +291,33 @@ void CIO::delayInt(unsigned int dly)
   delay(dly);
 }
 
+uint8_t CIO::getCPU() const
+{
+  return 0U;
+}
+
+// Code taken from https://github.com/emagii/at91sam3s/blob/master/examples/eefc_uniqueid/main.c
+void CIO::getUDID(uint8_t* buffer)
+{
+  uint32_t status;
+
+  EFC1->EEFC_FCR = (0x5A << 24) | EFC_FCMD_STUI;
+  do {
+    status = EFC1->EEFC_FSR;
+  } while ( (status & EEFC_FSR_FRDY) == EEFC_FSR_FRDY );
+
+  for (uint8_t i = 0; i < 16; i+=4) {
+    buffer[i + 0] = *(uint32_t *)(IFLASH1_ADDR + i) >> 24;
+    buffer[i + 1] = *(uint32_t *)(IFLASH1_ADDR + i) >> 16;
+    buffer[i + 2] = *(uint32_t *)(IFLASH1_ADDR + i) >>  8;
+    buffer[i + 3] = *(uint32_t *)(IFLASH1_ADDR + i) >>  0;
+  }
+
+  EFC1->EEFC_FCR = (0x5A << 24) | EFC_FCMD_SPUI;
+  do {
+    status = EFC1->EEFC_FSR;
+  } while ( (status & EEFC_FSR_FRDY) != EEFC_FSR_FRDY );
+}
+
 #endif
+

IOPins.h

@@ -59,12 +59,21 @@
 #elif defined(STM32F4_DVM)
     #include "pins/pins_f4_stm32dvm_v3.h"
 
+#elif defined(STM32F7_DVM)
+    #include "pins/pins_f7_stm32dvm_v5.h"
+
 #elif defined(DRCC_DVM_NQF)
     #include "pins/pins_f4_drcc_nqf.h"
 
+#elif defined(DRCC_DVM_HHP446)
+    #include "pins/pins_f4_drcc_hhp446.h"
+
+#elif defined(STM32F4_EDA_405) || defined(STM32F4_EDA_446)
+    #include "pins/pins_f4_stm32eda.h"
+
 #else
     #error "A valid board type macro need to be defined."
 
 #endif
 
-#endif  //#ifndef _IO_PINS_H
+#endif  //#ifndef _IO_PINS_H

IOSTM.cpp

@@ -106,6 +106,14 @@ void CIO::initInt()
    GPIO_Init(PORT_NXDN, &GPIO_InitStruct);
 #endif
 
+#if !defined(USE_ALTERNATE_M17_LEDS)
+   // M17 pin
+   RCC_AHB1PeriphClockCmd(RCC_Per_M17, ENABLE);
+   GPIO_InitStruct.GPIO_Pin   = PIN_M17;
+   GPIO_InitStruct.GPIO_Mode  = GPIO_Mode_OUT;
+   GPIO_Init(PORT_M17, &GPIO_InitStruct);
+#endif
+
 #if !defined(USE_ALTERNATE_POCSAG_LEDS)
    // POCSAG pin
    RCC_AHB1PeriphClockCmd(RCC_Per_POCSAG, ENABLE);
@@ -157,6 +165,14 @@ void CIO::initInt()
    GPIO_Init(PORT_MNXDN, &GPIO_InitStruct);
 #endif
 
+#if !defined(USE_ALTERNATE_M17_LEDS)
+   // M17 mode pin
+   RCC_AHB1PeriphClockCmd(RCC_Per_MM17, ENABLE);
+   GPIO_InitStruct.GPIO_Pin   = PIN_MM17;
+   GPIO_InitStruct.GPIO_Mode  = GPIO_Mode_OUT;
+   GPIO_Init(PORT_MM17, &GPIO_InitStruct);
+#endif
+
 #if !defined(USE_ALTERNATE_POCSAG_LEDS)
    // POCSAG mode pin
    RCC_AHB1PeriphClockCmd(RCC_Per_MPOCSAG, ENABLE);
@@ -326,25 +342,24 @@ void CIO::startInt()
 
 void CIO::interrupt()
 {
-   uint8_t control  = MARK_NONE;
-   uint16_t sample  = DC_OFFSET;
+   TSample sample = {DC_OFFSET, MARK_NONE};
    uint16_t rawRSSI = 0U;
 
-   m_txBuffer.get(sample, control);
+   m_txBuffer.get(sample);
 
    // Send the value to the DAC
 #if defined(STM32F4_NUCLEO) && defined(STM32F4_NUCLEO_ARDUINO_HEADER)
-   DAC_SetChannel2Data(DAC_Align_12b_R, sample);
+   DAC_SetChannel2Data(DAC_Align_12b_R, sample.sample);
 #else
-   DAC_SetChannel1Data(DAC_Align_12b_R, sample);
+   DAC_SetChannel1Data(DAC_Align_12b_R, sample.sample);
 #endif
 
    // Read value from ADC1 and ADC2
    if ((ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) == RESET)) {
       // shouldn't be still in reset at this point so null the sample value?
-      sample  = 0U;
+      sample.sample  = 0U;
    } else {
-      sample  = ADC_GetConversionValue(ADC1);
+      sample.sample  = ADC_GetConversionValue(ADC1);
 #if defined(SEND_RSSI_DATA)
       rawRSSI = ADC_GetConversionValue(ADC2);
 #endif
@@ -354,7 +369,7 @@ void CIO::interrupt()
    ADC_ClearFlag(ADC1, ADC_FLAG_EOC);
    ADC_SoftwareStartConv(ADC1);
 
-   m_rxBuffer.put(sample, control);
+   m_rxBuffer.put(sample);
    m_rssiBuffer.put(rawRSSI);
 
    m_watchdog++;
@@ -441,6 +456,27 @@ void CIO::setNXDNInt(bool on)
 #endif
 }
 
+void CIO::setM17Int(bool on)
+{
+#if defined(MODE_LEDS)
+#if defined(USE_ALTERNATE_M17_LEDS)
+   GPIO_WriteBit(PORT_DSTAR, PIN_DSTAR, on ? Bit_SET : Bit_RESET);
+   GPIO_WriteBit(PORT_P25,   PIN_P25, on ? Bit_SET : Bit_RESET);
+#else
+   GPIO_WriteBit(PORT_M17, PIN_M17, on ? Bit_SET : Bit_RESET);
+#endif
+#endif
+
+#if defined(MODE_PINS) && defined(STM32F4_NUCLEO_MORPHO_HEADER) && (defined(STM32F4_NUCLEO) || defined(STM32F722_RPT_HAT))
+#if defined(USE_ALTERNATE_M17_LEDS)
+   GPIO_WriteBit(PORT_MDSTAR, PIN_MDSTAR, on ? Bit_SET : Bit_RESET);
+   GPIO_WriteBit(PORT_MP25,   PIN_MP25,   on ? Bit_SET : Bit_RESET);
+#else
+   GPIO_WriteBit(PORT_MM17, PIN_MM17, on ? Bit_SET : Bit_RESET);
+#endif
+#endif
+}
+
 void CIO::setPOCSAGInt(bool on)
 {
 #if defined(MODE_LEDS)
@@ -509,4 +545,21 @@ void CIO::delayInt(unsigned int dly)
   }
 }
 
+uint8_t CIO::getCPU() const
+{
+  return 2U;
+}
+
+void CIO::getUDID(uint8_t* buffer)
+{
+#if defined(STM32F4XX)
+  ::memcpy(buffer, (void *)0x1FFF7A10, 12U);
+#elif defined(STM32F722xx)
+  ::memcpy(buffer, (void *)0x1FF07A10, 12U);
+#elif defined(STM32F767xx)
+  ::memcpy(buffer, (void *)0x1FF0F420, 12U);
 #endif
+}
+
+#endif
+

IOSTM_CMSIS.cpp

@@ -23,7 +23,6 @@
 #include "Globals.h"
 #include "IO.h"
 
-
 #if defined(STM32F1)
 
 #if defined(STM32F1_POG)
@@ -225,6 +224,9 @@ static inline void GPIOInit()
 #if !defined(USE_ALTERNATE_NXDN_LEDS)
   GPIOConfigPin(PORT_NXDN,   PIN_NXDN,   GPIO_CRL_MODE0_1);
 #endif
+#if !defined(USE_ALTERNATE_M17_LEDS)
+  GPIOConfigPin(PORT_M17,    PIN_M17,    GPIO_CRL_MODE0_1);
+#endif
 #if !defined(USE_ALTERNATE_POCSAG_LEDS)
   GPIOConfigPin(PORT_POCSAG, PIN_POCSAG, GPIO_CRL_MODE0_1);
 #endif
@@ -367,8 +369,7 @@ void CIO::startInt()
 
 void CIO::interrupt()
 {
-  uint8_t control  = MARK_NONE;
-  uint16_t sample  = DC_OFFSET;
+  TSample sample = {DC_OFFSET, MARK_NONE};
 #if defined(SEND_RSSI_DATA)
   uint16_t rawRSSI = 0U;
 #endif
@@ -385,12 +386,12 @@ void CIO::interrupt()
     *rssi_adon = 1;
 #endif
     
-    m_txBuffer.get(sample, control);
-    DAC->DHR12R1 = sample;  // Send the value to the DAC
+    m_txBuffer.get(sample);
+    DAC->DHR12R1 = sample.sample;  // Send the value to the DAC
 
     // Read value from ADC1 and ADC2
-    sample  = ADC1->DR;   // read conversion result; EOC is cleared by this read
-    m_rxBuffer.put(sample, control);
+    sample.sample  = ADC1->DR;   // read conversion result; EOC is cleared by this read
+    m_rxBuffer.put(sample);
 #if defined(SEND_RSSI_DATA)
     rawRSSI = ADC2->DR;
     m_rssiBuffer.put(rawRSSI);
@@ -450,6 +451,16 @@ void CIO::setNXDNInt(bool on)
 #endif
 }
 
+void CIO::setM17Int(bool on)
+{
+#if defined(USE_ALTERNATE_M17_LEDS)
+  BB_DSTAR = !!on;
+  BB_P25   = !!on;
+#else
+  BB_M17 = !!on;
+#endif
+}
+
 void CIO::setPOCSAGInt(bool on)
 {
 #if defined(USE_ALTERNATE_POCSAG_LEDS)
@@ -473,4 +484,17 @@ void CIO::delayInt(unsigned int dly)
   delay(dly);
 }
 
+uint8_t CIO::getCPU() const
+{
+  return 2U;
+}
+
+void CIO::getUDID(uint8_t* buffer)
+{
+#if defined(STM32F105xC)
+  ::memcpy(buffer, (void *)0x1FFFF7E8, 12U);
 #endif
+}
+
+#endif
+

IOTeensy.cpp

@@ -75,6 +75,9 @@ void CIO::initInt()
 #if !defined(USE_ALTERNATE_NXDN_LEDS)
   pinMode(PIN_NXDN,   OUTPUT);
 #endif
+#if !defined(USE_ALTERNATE_M17_LEDS)
+  pinMode(PIN_M17,    OUTPUT);
+#endif
 #if !defined(USE_ALTERNATE_POCSAG_LEDS)
   pinMode(PIN_POCSAG, OUTPUT);
 #endif
@@ -161,15 +164,14 @@ void CIO::startInt()
 
 void CIO::interrupt()
 {
-  uint8_t control = MARK_NONE;
-  uint16_t sample = DC_OFFSET;
+   TSample sample = {DC_OFFSET, MARK_NONE};
 
-  m_txBuffer.get(sample, control);
-  *(int16_t *)&(DAC0_DAT0L) = sample;
+  m_txBuffer.get(sample);
+  *(int16_t *)&(DAC0_DAT0L) = sample.sample;
 
   if ((ADC0_SC1A & ADC_SC1_COCO) == ADC_SC1_COCO) {
-    sample = ADC0_RA;
-    m_rxBuffer.put(sample, control);
+    sample.sample = ADC0_RA;
+    m_rxBuffer.put(sample);
   }
     
 #if defined(SEND_RSSI_DATA)
@@ -238,6 +240,16 @@ void CIO::setNXDNInt(bool on)
 #endif
 }
 
+void CIO::setM17Int(bool on)
+{
+#if defined(USE_ALTERNATE_M17_LEDS)
+  digitalWrite(PIN_DSTAR, on ? HIGH : LOW);
+  digitalWrite(PIN_P25,   on ? HIGH : LOW);
+#else
+  digitalWrite(PIN_M17, on ? HIGH : LOW);
+#endif
+}
+
 void CIO::setPOCSAGInt(bool on)
 {
 #if defined(USE_ALTERNATE_POCSAG_LEDS)
@@ -263,4 +275,15 @@ void CIO::delayInt(unsigned int dly)
   delay(dly);
 }
 
+uint8_t CIO::getCPU() const
+{
+  return 1U;
+}
+
+void CIO::getUDID(uint8_t* buffer)
+{
+  ::memcpy(buffer, (void *)0x4058, 16U);
+}
+
 #endif
+

M17Defines.h

@@ -0,0 +1,67 @@
+/*
+ *   Copyright (C) 2016,2017,2018,2020,2021 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if !defined(M17DEFINES_H)
+#define  M17DEFINES_H
+
+const unsigned int M17_RADIO_SYMBOL_LENGTH = 5U;      // At 24 kHz sample rate
+
+const unsigned int M17_FRAME_LENGTH_BITS    = 384U;
+const unsigned int M17_FRAME_LENGTH_BYTES   = M17_FRAME_LENGTH_BITS / 8U;
+const unsigned int M17_FRAME_LENGTH_SYMBOLS = M17_FRAME_LENGTH_BITS / 2U;
+const unsigned int M17_FRAME_LENGTH_SAMPLES = M17_FRAME_LENGTH_SYMBOLS * M17_RADIO_SYMBOL_LENGTH;
+
+const unsigned int M17_SYNC_LENGTH_BITS    = 16U;
+const unsigned int M17_SYNC_LENGTH_BYTES   = M17_SYNC_LENGTH_BITS / 8U;
+const unsigned int M17_SYNC_LENGTH_SYMBOLS = M17_SYNC_LENGTH_BITS / 2U;
+const unsigned int M17_SYNC_LENGTH_SAMPLES = M17_SYNC_LENGTH_SYMBOLS * M17_RADIO_SYMBOL_LENGTH;
+
+const uint8_t M17_LINK_SETUP_SYNC_BYTES[] = {0x55U, 0xF7U};
+const uint8_t M17_STREAM_SYNC_BYTES[]     = {0xFFU, 0x5DU};
+const uint8_t M17_EOF_SYNC_BYTES[]        = {0x55U, 0x5DU};
+
+const uint16_t M17_LINK_SETUP_SYNC_BITS = 0x55F7U;
+const uint16_t M17_STREAM_SYNC_BITS     = 0xFF5DU;
+const uint16_t M17_EOF_SYNC_BITS        = 0x555DU;
+
+// 5     5     F     7
+// 01 01 01 01 11 11 01 11
+// +3 +3 +3 +3 -3 -3 +3 -3
+
+const int8_t M17_LINK_SETUP_SYNC_SYMBOLS_VALUES[] = {+3, +3, +3, +3, -3, -3, +3, -3};
+
+const uint8_t M17_LINK_SETUP_SYNC_SYMBOLS = 0xF2U;
+
+// F     F     5     D
+// 11 11 11 11 01 01 11 01
+// -3 -3 -3 -3 +3 +3 -3 +3
+
+const int8_t M17_STREAM_SYNC_SYMBOLS_VALUES[] = {-3, -3, -3, -3, +3, +3, -3, +3};
+
+const uint8_t M17_STREAM_SYNC_SYMBOLS = 0x0DU;
+
+// 5     5     5     D
+// 01 01 01 01 01 01 11 01
+// +3 +3 +3 +3 +3 +3 -3 +3
+
+const int8_t M17_EOF_SYNC_SYMBOLS_VALUES[] = {+3, +3, +3, +3, +3, +3, -3, +3};
+
+const uint8_t M17_EOF_SYNC_SYMBOLS = 0xFDU;
+
+#endif
+

M17RX.cpp

@@ -0,0 +1,485 @@
+/*
+ *   Copyright (C) 2009-2017,2020,2021 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_M17)
+
+#include "Globals.h"
+#include "M17RX.h"
+#include "Utils.h"
+
+const q15_t SCALING_FACTOR = 18750;      // Q15(0.55)
+
+const uint8_t MAX_SYNC_BIT_START_ERRS = 0U;
+const uint8_t MAX_SYNC_BIT_RUN_ERRS   = 2U;
+
+const uint8_t MAX_SYNC_SYMBOL_START_ERRS = 0U;
+const uint8_t MAX_SYNC_SYMBOL_RUN_ERRS   = 1U;
+
+const uint8_t BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U};
+
+#define WRITE_BIT1(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
+
+const uint8_t NOAVEPTR = 99U;
+
+const uint16_t NOENDPTR = 9999U;
+
+const unsigned int MAX_SYNC_FRAMES = 3U + 1U;
+
+CM17RX::CM17RX() :
+m_state(M17RXS_NONE),
+m_bitBuffer(),
+m_buffer(),
+m_bitPtr(0U),
+m_dataPtr(0U),
+m_startPtr(NOENDPTR),
+m_endPtr(NOENDPTR),
+m_syncPtr(NOENDPTR),
+m_minSyncPtr(NOENDPTR),
+m_maxSyncPtr(NOENDPTR),
+m_maxCorr(0),
+m_lostCount(0U),
+m_countdown(0U),
+m_nextState(M17RXS_NONE),
+m_centre(),
+m_centreVal(0),
+m_threshold(),
+m_thresholdVal(0),
+m_averagePtr(NOAVEPTR),
+m_rssiAccum(0U),
+m_rssiCount(0U)
+{
+}
+
+void CM17RX::reset()
+{
+  m_state        = M17RXS_NONE;
+  m_dataPtr      = 0U;
+  m_bitPtr       = 0U;
+  m_maxCorr      = 0;
+  m_averagePtr   = NOAVEPTR;
+  m_startPtr     = NOENDPTR;
+  m_endPtr       = NOENDPTR;
+  m_syncPtr      = NOENDPTR;
+  m_minSyncPtr   = NOENDPTR;
+  m_maxSyncPtr   = NOENDPTR;
+  m_centreVal    = 0;
+  m_thresholdVal = 0;
+  m_lostCount    = 0U;
+  m_countdown    = 0U;
+  m_nextState    = M17RXS_NONE;
+  m_rssiAccum    = 0U;
+  m_rssiCount    = 0U;
+}
+
+void CM17RX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length)
+{
+  for (uint8_t i = 0U; i < length; i++) {
+    q15_t sample = samples[i];
+
+    m_rssiAccum += rssi[i];
+    m_rssiCount++;
+
+    m_bitBuffer[m_bitPtr] <<= 1;
+    if (sample < 0)
+      m_bitBuffer[m_bitPtr] |= 0x01U;
+
+    m_buffer[m_dataPtr] = sample;
+
+    switch (m_state) {
+    case M17RXS_LINK_SETUP:
+    case M17RXS_STREAM:
+      processData(sample);
+      break;
+    default:
+      processNone(sample);
+      break;
+    }
+
+    m_dataPtr++;
+    if (m_dataPtr >= M17_FRAME_LENGTH_SAMPLES)
+      m_dataPtr = 0U;
+
+    m_bitPtr++;
+    if (m_bitPtr >= M17_RADIO_SYMBOL_LENGTH)
+      m_bitPtr = 0U;
+  }
+}
+
+void CM17RX::processNone(q15_t sample)
+{
+  bool ret1 = correlateSync(M17_LINK_SETUP_SYNC_SYMBOLS, M17_LINK_SETUP_SYNC_SYMBOLS_VALUES, M17_LINK_SETUP_SYNC_BYTES, MAX_SYNC_SYMBOL_START_ERRS, MAX_SYNC_BIT_START_ERRS);
+  bool ret2 = correlateSync(M17_STREAM_SYNC_SYMBOLS,     M17_STREAM_SYNC_SYMBOLS_VALUES,     M17_STREAM_SYNC_BYTES,     MAX_SYNC_SYMBOL_START_ERRS, MAX_SYNC_BIT_START_ERRS);
+
+  if (ret1 || ret2) {
+    // On the first sync, start the countdown to the state change
+    if (m_countdown == 0U) {
+      m_rssiAccum = 0U;
+      m_rssiCount = 0U;
+
+      io.setDecode(true);
+      io.setADCDetection(true);
+
+      m_averagePtr = NOAVEPTR;
+
+      m_countdown = 5U;
+      
+      if (ret1) m_nextState = M17RXS_LINK_SETUP;
+      if (ret2) m_nextState = M17RXS_STREAM;
+    }
+  }
+
+  if (m_countdown > 0U)
+    m_countdown--;
+
+  if (m_countdown == 1U) {
+    m_minSyncPtr = m_syncPtr + M17_FRAME_LENGTH_SAMPLES - 1U;
+    if (m_minSyncPtr >= M17_FRAME_LENGTH_SAMPLES)
+      m_minSyncPtr -= M17_FRAME_LENGTH_SAMPLES;
+
+    m_maxSyncPtr = m_syncPtr + 1U;
+    if (m_maxSyncPtr >= M17_FRAME_LENGTH_SAMPLES)
+      m_maxSyncPtr -= M17_FRAME_LENGTH_SAMPLES;
+
+    m_state     = m_nextState;
+    m_countdown = 0U;
+    m_nextState = M17RXS_NONE;
+  }
+}
+
+void CM17RX::processData(q15_t sample)
+{
+  bool eof = false;
+
+  if (m_minSyncPtr < m_maxSyncPtr) {
+    if (m_dataPtr >= m_minSyncPtr && m_dataPtr <= m_maxSyncPtr) {
+      bool ret = correlateSync(M17_STREAM_SYNC_SYMBOLS, M17_STREAM_SYNC_SYMBOLS_VALUES, M17_STREAM_SYNC_BYTES,  MAX_SYNC_SYMBOL_RUN_ERRS, MAX_SYNC_BIT_RUN_ERRS);
+
+      eof = correlateSync(M17_EOF_SYNC_SYMBOLS, M17_EOF_SYNC_SYMBOLS_VALUES, M17_EOF_SYNC_BYTES, MAX_SYNC_SYMBOL_RUN_ERRS, MAX_SYNC_BIT_RUN_ERRS);
+
+      if (ret) m_state = M17RXS_STREAM;
+    }
+  } else {
+    if (m_dataPtr >= m_minSyncPtr || m_dataPtr <= m_maxSyncPtr) {
+      bool ret = correlateSync(M17_STREAM_SYNC_SYMBOLS, M17_STREAM_SYNC_SYMBOLS_VALUES, M17_STREAM_SYNC_BYTES,  MAX_SYNC_SYMBOL_RUN_ERRS, MAX_SYNC_BIT_RUN_ERRS);
+
+      eof = correlateSync(M17_EOF_SYNC_SYMBOLS, M17_EOF_SYNC_SYMBOLS_VALUES, M17_EOF_SYNC_BYTES, MAX_SYNC_SYMBOL_RUN_ERRS, MAX_SYNC_BIT_RUN_ERRS);
+
+      if (ret) m_state = M17RXS_STREAM;
+    }
+  }
+
+  if (eof) {
+    DEBUG4("M17RX: eof sync found pos/centre/threshold", m_syncPtr, m_centreVal, m_thresholdVal);
+
+    io.setDecode(false);
+    io.setADCDetection(false);
+
+    serial.writeM17EOT();
+
+    m_state      = M17RXS_NONE;
+    m_endPtr     = NOENDPTR;
+    m_averagePtr = NOAVEPTR;
+    m_countdown  = 0U;
+    m_nextState  = M17RXS_NONE;
+    m_maxCorr    = 0;
+  }
+
+  if (m_dataPtr == m_endPtr) {
+    // Only update the centre and threshold if they are from a good sync
+    if (m_lostCount == MAX_SYNC_FRAMES) {
+      m_minSyncPtr = m_syncPtr + M17_FRAME_LENGTH_SAMPLES - 1U;
+      if (m_minSyncPtr >= M17_FRAME_LENGTH_SAMPLES)
+        m_minSyncPtr -= M17_FRAME_LENGTH_SAMPLES;
+
+      m_maxSyncPtr = m_syncPtr + 1U;
+      if (m_maxSyncPtr >= M17_FRAME_LENGTH_SAMPLES)
+        m_maxSyncPtr -= M17_FRAME_LENGTH_SAMPLES;
+    }
+
+    calculateLevels(m_startPtr, M17_FRAME_LENGTH_SYMBOLS);
+
+    switch (m_state) {
+      case M17RXS_LINK_SETUP:
+        DEBUG4("M17RX: link setup sync found pos/centre/threshold", m_syncPtr, m_centreVal, m_thresholdVal);
+        break;
+      case M17RXS_STREAM:
+        DEBUG4("M17RX: stream sync found pos/centre/threshold", m_syncPtr, m_centreVal, m_thresholdVal);
+        break;
+      default:
+        break;  
+    }
+
+    uint8_t frame[M17_FRAME_LENGTH_BYTES + 3U];
+    samplesToBits(m_startPtr, M17_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal);
+
+    // We've not seen a stream sync for too long, signal RXLOST and change to RX_NONE
+    m_lostCount--;
+    if (m_lostCount == 0U) {
+      DEBUG1("M17RX: sync timed out, lost lock");
+
+      io.setDecode(false);
+      io.setADCDetection(false);
+
+      serial.writeM17Lost();
+
+      m_state      = M17RXS_NONE;
+      m_endPtr     = NOENDPTR;
+      m_averagePtr = NOAVEPTR;
+      m_countdown  = 0U;
+      m_nextState  = M17RXS_NONE;
+      m_maxCorr    = 0;
+    } else {
+      frame[0U] = m_lostCount == (MAX_SYNC_FRAMES - 1U) ? 0x01U : 0x00U;
+
+      switch (m_state) {
+        case M17RXS_LINK_SETUP:
+          writeRSSILinkSetup(frame);
+          break;
+        case M17RXS_STREAM:
+          writeRSSIStream(frame);
+          break;
+        default:
+          break;  
+      }
+
+      m_maxCorr   = 0;
+      m_nextState = M17RXS_NONE;
+    }
+  }
+}
+
+bool CM17RX::correlateSync(uint8_t syncSymbols, const int8_t* syncSymbolValues, const uint8_t* syncBytes, uint8_t maxSymbolErrs, uint8_t maxBitErrs)
+{
+  if (countBits8(m_bitBuffer[m_bitPtr] ^ syncSymbols) <= maxSymbolErrs) {
+    uint16_t ptr = m_dataPtr + M17_FRAME_LENGTH_SAMPLES - M17_SYNC_LENGTH_SAMPLES + M17_RADIO_SYMBOL_LENGTH;
+    if (ptr >= M17_FRAME_LENGTH_SAMPLES)
+      ptr -= M17_FRAME_LENGTH_SAMPLES;
+
+    q31_t corr = 0;
+    q15_t min =  16000;
+    q15_t max = -16000;
+
+    for (uint8_t i = 0U; i < M17_SYNC_LENGTH_SYMBOLS; i++) {
+      q15_t val = m_buffer[ptr];
+
+      if (val > max)
+        max = val;
+      if (val < min)
+        min = val;
+
+      switch (syncSymbolValues[i]) {
+      case +3:
+        corr -= (val + val + val);
+        break;
+      case +1:
+        corr -= val;
+        break;
+      case -1:
+        corr += val;
+        break;
+      default:  // -3
+        corr += (val + val + val);
+        break;
+      }
+
+      ptr += M17_RADIO_SYMBOL_LENGTH;
+      if (ptr >= M17_FRAME_LENGTH_SAMPLES)
+        ptr -= M17_FRAME_LENGTH_SAMPLES;
+    }
+
+    if (corr > m_maxCorr) {
+      if (m_averagePtr == NOAVEPTR) {
+        m_centreVal = (max + min) >> 1;
+
+        q31_t v1 = (max - m_centreVal) * SCALING_FACTOR;
+        m_thresholdVal = q15_t(v1 >> 15);
+      }
+
+      uint16_t startPtr = m_dataPtr + M17_FRAME_LENGTH_SAMPLES - M17_SYNC_LENGTH_SAMPLES + M17_RADIO_SYMBOL_LENGTH;
+      if (startPtr >= M17_FRAME_LENGTH_SAMPLES)
+        startPtr -= M17_FRAME_LENGTH_SAMPLES;
+
+      uint8_t sync[M17_SYNC_LENGTH_BYTES];
+      samplesToBits(startPtr, M17_SYNC_LENGTH_SYMBOLS, sync, 0U, m_centreVal, m_thresholdVal);
+
+      uint8_t errs = 0U;
+      for (uint8_t i = 0U; i < M17_SYNC_LENGTH_BYTES; i++)
+        errs += countBits8(sync[i] ^ syncBytes[i]);
+
+      if (errs <= maxBitErrs) {
+        m_maxCorr   = corr;
+        m_lostCount = MAX_SYNC_FRAMES;
+        m_syncPtr   = m_dataPtr;
+
+        m_startPtr = startPtr;
+
+        m_endPtr = m_dataPtr + M17_FRAME_LENGTH_SAMPLES - M17_SYNC_LENGTH_SAMPLES - 1U;
+        if (m_endPtr >= M17_FRAME_LENGTH_SAMPLES)
+          m_endPtr -= M17_FRAME_LENGTH_SAMPLES;
+
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+void CM17RX::calculateLevels(uint16_t start, uint16_t count)
+{
+  q15_t maxPos = -16000;
+  q15_t minPos =  16000;
+  q15_t maxNeg =  16000;
+  q15_t minNeg = -16000;
+
+  for (uint16_t i = 0U; i < count; i++) {
+    q15_t sample = m_buffer[start];
+
+    if (sample > 0) {
+      if (sample > maxPos)
+        maxPos = sample;
+      if (sample < minPos)
+        minPos = sample;
+    } else {
+      if (sample < maxNeg)
+        maxNeg = sample;
+      if (sample > minNeg)
+        minNeg = sample;
+    }
+
+    start += M17_RADIO_SYMBOL_LENGTH;
+    if (start >= M17_FRAME_LENGTH_SAMPLES)
+      start -= M17_FRAME_LENGTH_SAMPLES;
+  }
+
+  q15_t posThresh = (maxPos + minPos) >> 1;
+  q15_t negThresh = (maxNeg + minNeg) >> 1;
+
+  q15_t centre = (posThresh + negThresh) >> 1;
+
+  q15_t threshold = posThresh - centre;
+
+  DEBUG5("M17RX: pos/neg/centre/threshold", posThresh, negThresh, centre, threshold);
+
+  if (m_averagePtr == NOAVEPTR) {
+    for (uint8_t i = 0U; i < 16U; i++) {
+      m_centre[i] = centre;
+      m_threshold[i] = threshold;
+    }
+
+    m_averagePtr = 0U;
+  } else {
+    m_centre[m_averagePtr] = centre;
+    m_threshold[m_averagePtr] = threshold;
+
+    m_averagePtr++;
+    if (m_averagePtr >= 16U)
+      m_averagePtr = 0U;
+  }
+
+  m_centreVal = 0;
+  m_thresholdVal = 0;
+
+  for (uint8_t i = 0U; i < 16U; i++) {
+    m_centreVal += m_centre[i];
+    m_thresholdVal += m_threshold[i];
+  }
+
+  m_centreVal >>= 4;
+  m_thresholdVal >>= 4;
+}
+
+void CM17RX::samplesToBits(uint16_t start, uint16_t count, uint8_t* buffer, uint16_t offset, q15_t centre, q15_t threshold)
+{
+  for (uint16_t i = 0U; i < count; i++) {
+    q15_t sample = m_buffer[start] - centre;
+
+    if (sample < -threshold) {
+      WRITE_BIT1(buffer, offset, false);
+      offset++;
+      WRITE_BIT1(buffer, offset, true);
+      offset++;
+    } else if (sample < 0) {
+      WRITE_BIT1(buffer, offset, false);
+      offset++;
+      WRITE_BIT1(buffer, offset, false);
+      offset++;
+    } else if (sample < threshold) {
+      WRITE_BIT1(buffer, offset, true);
+      offset++;
+      WRITE_BIT1(buffer, offset, false);
+      offset++;
+    } else {
+      WRITE_BIT1(buffer, offset, true);
+      offset++;
+      WRITE_BIT1(buffer, offset, true);
+      offset++;
+    }
+
+    start += M17_RADIO_SYMBOL_LENGTH;
+    if (start >= M17_FRAME_LENGTH_SAMPLES)
+      start -= M17_FRAME_LENGTH_SAMPLES;
+  }
+}
+
+void CM17RX::writeRSSILinkSetup(uint8_t* data)
+{
+#if defined(SEND_RSSI_DATA)
+  if (m_rssiCount > 0U) {
+    uint16_t rssi = m_rssiAccum / m_rssiCount;
+
+    data[49U] = (rssi >> 8) & 0xFFU;
+    data[50U] = (rssi >> 0) & 0xFFU;
+
+    serial.writeM17LinkSetup(data, M17_FRAME_LENGTH_BYTES + 3U);
+  } else {
+    serial.writeM17LinkSetup(data, M17_FRAME_LENGTH_BYTES + 1U);
+  }
+#else
+  serial.writeM17LinkSetup(data, M17_FRAME_LENGTH_BYTES + 1U);
+#endif
+
+  m_rssiAccum = 0U;
+  m_rssiCount = 0U;
+}
+
+void CM17RX::writeRSSIStream(uint8_t* data)
+{
+#if defined(SEND_RSSI_DATA)
+  if (m_rssiCount > 0U) {
+    uint16_t rssi = m_rssiAccum / m_rssiCount;
+
+    data[49U] = (rssi >> 8) & 0xFFU;
+    data[50U] = (rssi >> 0) & 0xFFU;
+
+    serial.writeM17Stream(data, M17_FRAME_LENGTH_BYTES + 3U);
+  } else {
+    serial.writeM17Stream(data, M17_FRAME_LENGTH_BYTES + 1U);
+  }
+#else
+  serial.writeM17Stream(data, M17_FRAME_LENGTH_BYTES + 1U);
+#endif
+
+  m_rssiAccum = 0U;
+  m_rssiCount = 0U;
+}
+
+#endif
+

M17RX.h

@@ -0,0 +1,77 @@
+/*
+ *   Copyright (C) 2015,2016,2017,2020,2021 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_M17)
+
+#if !defined(M17RX_H)
+#define  M17RX_H
+
+#include "M17Defines.h"
+
+enum M17RX_STATE {
+  M17RXS_NONE,
+  M17RXS_LINK_SETUP,
+  M17RXS_STREAM
+};
+
+class CM17RX {
+public:
+  CM17RX();
+
+  void samples(const q15_t* samples, uint16_t* rssi, uint8_t length);
+
+  void reset();
+
+private:
+  M17RX_STATE m_state;
+  uint8_t     m_bitBuffer[M17_RADIO_SYMBOL_LENGTH];
+  q15_t       m_buffer[M17_FRAME_LENGTH_SAMPLES];
+  uint16_t    m_bitPtr;
+  uint16_t    m_dataPtr;
+  uint16_t    m_startPtr;
+  uint16_t    m_endPtr;
+  uint16_t    m_syncPtr;
+  uint16_t    m_minSyncPtr;
+  uint16_t    m_maxSyncPtr;
+  q31_t       m_maxCorr;
+  uint16_t    m_lostCount;
+  uint8_t     m_countdown;
+  M17RX_STATE m_nextState;
+  q15_t       m_centre[16U];
+  q15_t       m_centreVal;
+  q15_t       m_threshold[16U];
+  q15_t       m_thresholdVal;
+  uint8_t     m_averagePtr;
+  uint32_t    m_rssiAccum;
+  uint16_t    m_rssiCount;
+
+  void processNone(q15_t sample);
+  void processData(q15_t sample);
+  bool correlateSync(uint8_t syncSymbols, const int8_t* syncSymbolValues, const uint8_t* syncBytes, uint8_t maxSymbolErrs, uint8_t maxBitErrs);
+  void calculateLevels(uint16_t start, uint16_t count);
+  void samplesToBits(uint16_t start, uint16_t count, uint8_t* buffer, uint16_t offset, q15_t centre, q15_t threshold);
+  void writeRSSILinkSetup(uint8_t* data);
+  void writeRSSIStream(uint8_t* data);
+};
+
+#endif
+
+#endif
+

M17TX.cpp

@@ -0,0 +1,190 @@
+/*
+ *   Copyright (C) 2009-2018,2020,2021 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2017 by Andy Uribe CA6JAU
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_M17)
+
+#include "Globals.h"
+#include "M17TX.h"
+
+#include "M17Defines.h"
+
+// Generated using rcosdesign(0.5, 8, 5, 'sqrt') in MATLAB
+static q15_t RRC_0_5_FILTER[] = {0, 0, 0, 0, -290, -174, 142, 432, 438, 90, -387, -561, -155, 658, 1225, 767,
+				  -980, -3326, -4648, -3062, 2527, 11552, 21705, 29724, 32767, 29724, 21705,
+				  11552, 2527, -3062, -4648, -3326, -980, 767, 1225, 658, -155, -561, -387, 90,
+				  438, 432, 142, -174, -290}; // numTaps = 45, L = 5
+const uint16_t RRC_0_5_FILTER_PHASE_LEN = 9U; // phaseLength = numTaps/L
+
+const q15_t M17_LEVELA =  1481;
+const q15_t M17_LEVELB =  494;
+const q15_t M17_LEVELC = -494;
+const q15_t M17_LEVELD = -1481;
+
+const uint8_t M17_START_SYNC = 0x77U;
+const uint8_t M17_END_SYNC   = 0xFFU;
+const uint8_t M17_HANG       = 0x00U;
+
+CM17TX::CM17TX() :
+m_buffer(TX_BUFFER_LEN),
+m_modFilter(),
+m_modState(),
+m_poBuffer(),
+m_poLen(0U),
+m_poPtr(0U),
+m_txDelay(240U),      // 200ms
+m_txHang(4800U),      // 4s
+m_txCount(0U)
+{
+  ::memset(m_modState, 0x00U, 16U * sizeof(q15_t));
+
+  m_modFilter.L           = M17_RADIO_SYMBOL_LENGTH;
+  m_modFilter.phaseLength = RRC_0_5_FILTER_PHASE_LEN;
+  m_modFilter.pCoeffs     = RRC_0_5_FILTER;
+  m_modFilter.pState      = m_modState;
+}
+
+void CM17TX::process()
+{
+  // If we have M17 data to transmit, do so.
+  if (m_poLen == 0U && m_buffer.getData() > 0U) {
+    if (!m_tx) {
+      for (uint16_t i = 0U; i < m_txDelay; i++)
+        m_poBuffer[m_poLen++] = M17_START_SYNC;
+    } else {
+      for (uint8_t i = 0U; i < M17_FRAME_LENGTH_BYTES; i++) {
+        uint8_t c = 0U;
+        m_buffer.get(c);
+        m_poBuffer[m_poLen++] = c;
+      }
+    }
+
+    m_poPtr = 0U;
+  }
+
+  if (m_poLen > 0U) {
+    // Transmit M17 data.
+    uint16_t space = io.getSpace();
+
+    while (space > (4U * M17_RADIO_SYMBOL_LENGTH)) {
+      uint8_t c = m_poBuffer[m_poPtr++];
+      writeByte(c);
+
+      // Reduce space and reset the hang timer.
+      space -= 4U * M17_RADIO_SYMBOL_LENGTH;
+      if (m_duplex)
+        m_txCount = m_txHang;
+
+      if (m_poPtr >= m_poLen) {
+        m_poPtr = 0U;
+        m_poLen = 0U;
+        return;
+      }
+    }
+  } else if (m_txCount > 0U) {
+    // Transmit silence until the hang timer has expired.
+    uint16_t space = io.getSpace();
+
+    while (space > (4U * M17_RADIO_SYMBOL_LENGTH)) {
+      writeSilence();
+
+      space -= 4U * M17_RADIO_SYMBOL_LENGTH;
+      m_txCount--;
+
+      if (m_txCount == 0U)
+        return;
+    }
+  }
+}
+
+uint8_t CM17TX::writeData(const uint8_t* data, uint8_t length)
+{
+  if (length != (M17_FRAME_LENGTH_BYTES + 1U))
+    return 4U;
+
+  uint16_t space = m_buffer.getSpace();
+  if (space < M17_FRAME_LENGTH_BYTES)
+    return 5U;
+
+  for (uint8_t i = 0U; i < M17_FRAME_LENGTH_BYTES; i++)
+    m_buffer.put(data[i + 1U]);
+
+  return 0U;
+}
+
+void CM17TX::writeByte(uint8_t c)
+{
+  q15_t inBuffer[4U];
+  q15_t outBuffer[M17_RADIO_SYMBOL_LENGTH * 4U];
+
+  const uint8_t MASK = 0xC0U;
+
+  for (uint8_t i = 0U; i < 4U; i++, c <<= 2) {
+    switch (c & MASK) {
+      case 0xC0U:
+        inBuffer[i] = M17_LEVELA;
+        break;
+      case 0x80U:
+        inBuffer[i] = M17_LEVELB;
+        break;
+      case 0x00U:
+        inBuffer[i] = M17_LEVELC;
+        break;
+      default:
+        inBuffer[i] = M17_LEVELD;
+        break;
+    }
+  }
+
+  ::arm_fir_interpolate_q15(&m_modFilter, inBuffer, outBuffer, 4U);
+
+  io.write(STATE_M17, outBuffer, M17_RADIO_SYMBOL_LENGTH * 4U);
+}
+
+void CM17TX::writeSilence()
+{
+  q15_t inBuffer[4U] = {0x00U, 0x00U, 0x00U, 0x00U};
+  q15_t outBuffer[M17_RADIO_SYMBOL_LENGTH * 4U];
+
+  ::arm_fir_interpolate_q15(&m_modFilter, inBuffer, outBuffer, 4U);
+
+  io.write(STATE_M17, outBuffer, M17_RADIO_SYMBOL_LENGTH * 4U);
+}
+
+void CM17TX::setTXDelay(uint8_t delay)
+{
+  m_txDelay = 600U + uint16_t(delay) * 12U;        // 500ms + tx delay
+
+  if (m_txDelay > 1200U)
+    m_txDelay = 1200U;
+}
+
+uint8_t CM17TX::getSpace() const
+{
+  return m_buffer.getSpace() / M17_FRAME_LENGTH_BYTES;
+}
+
+void CM17TX::setParams(uint8_t txHang)
+{
+  m_txHang = txHang * 1200U;
+}
+
+#endif
+

M17TX.h

@@ -0,0 +1,60 @@
+/*
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+
+#if defined(MODE_M17)
+
+#if !defined(M17TX_H)
+#define  M17TX_H
+
+#include "RingBuffer.h"
+
+class CM17TX {
+public:
+  CM17TX();
+
+  uint8_t writeData(const uint8_t* data, uint8_t length);
+
+  void process();
+
+  void setTXDelay(uint8_t delay);
+
+  uint8_t getSpace() const;
+
+  void setParams(uint8_t txHang);
+
+private:
+  CRingBuffer<uint8_t>             m_buffer;
+  arm_fir_interpolate_instance_q15 m_modFilter;
+  q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare
+  uint8_t                          m_poBuffer[1200U];
+  uint16_t                         m_poLen;
+  uint16_t                         m_poPtr;
+  uint16_t                         m_txDelay;
+  uint32_t                         m_txHang;
+  uint32_t                         m_txCount;
+
+  void writeByte(uint8_t c);
+  void writeSilence();
+};
+
+#endif
+
+#endif
+

MMDVM.cpp

@@ -31,45 +31,75 @@ bool m_dmrEnable    = true;
 bool m_ysfEnable    = true;
 bool m_p25Enable    = true;
 bool m_nxdnEnable   = true;
+bool m_m17Enable    = true;
 bool m_pocsagEnable = true;
 bool m_fmEnable     = true;
+bool m_ax25Enable   = true;
 
 bool m_duplex = true;
 
 bool m_tx  = false;
 bool m_dcd = false;
 
-CDStarRX   dstarRX;
-CDStarTX   dstarTX;
-
-CDMRIdleRX dmrIdleRX;
-CDMRRX     dmrRX;
-CDMRTX     dmrTX;
-
-CDMRDMORX  dmrDMORX;
-CDMRDMOTX  dmrDMOTX;
-
-CYSFRX     ysfRX;
-CYSFTX     ysfTX;
-
-CP25RX     p25RX;
-CP25TX     p25TX;
-
-CNXDNRX    nxdnRX;
-CNXDNTX    nxdnTX;
-
-CPOCSAGTX  pocsagTX;
-
-CFM        fm;
+#if defined(MODE_DSTAR)
+CDStarRX dstarRX;
+CDStarTX dstarTX;
 
 CCalDStarRX calDStarRX;
 CCalDStarTX calDStarTX;
-CCalDMR     calDMR;
-CCalP25     calP25;
-CCalNXDN    calNXDN;
-CCalFM      calFM;
-CCalPOCSAG  calPOCSAG;
-CCalRSSI    calRSSI;
+#endif
+
+#if defined(MODE_DMR)
+CDMRIdleRX dmrIdleRX;
+CDMRRX dmrRX;
+CDMRTX dmrTX;
+
+CDMRDMORX dmrDMORX;
+CDMRDMOTX dmrDMOTX;
+
+CCalDMR calDMR;
+#endif
+
+#if defined(MODE_YSF)
+CYSFRX ysfRX;
+CYSFTX ysfTX;
+#endif
+
+#if defined(MODE_P25)
+CP25RX p25RX;
+CP25TX p25TX;
+
+CCalP25 calP25;
+#endif
+
+#if defined(MODE_NXDN)
+CNXDNRX nxdnRX;
+CNXDNTX nxdnTX;
+
+CCalNXDN calNXDN;
+#endif
+
+#if defined(MODE_M17)
+CM17RX m17RX;
+CM17TX m17TX;
+#endif
+
+#if defined(MODE_POCSAG)
+CPOCSAGTX  pocsagTX;
+CCalPOCSAG calPOCSAG;
+#endif
+
+#if defined(MODE_FM)
+CFM    fm;
+CCalFM calFM;
+#endif
+
+#if defined(MODE_AX25)
+CAX25RX ax25RX;
+CAX25TX ax25TX;
+#endif
+
+CCalRSSI calRSSI;
 
 CCWIdTX cwIdTX;
 
@@ -88,48 +118,84 @@ void loop()
   io.process();
 
   // The following is for transmitting
+#if defined(MODE_DSTAR)
   if (m_dstarEnable && m_modemState == STATE_DSTAR)
     dstarTX.process();
+#endif
 
+#if defined(MODE_DMR)
   if (m_dmrEnable && m_modemState == STATE_DMR) {
     if (m_duplex)
       dmrTX.process();
     else
       dmrDMOTX.process();
   }
+#endif
 
+#if defined(MODE_YSF)
   if (m_ysfEnable && m_modemState == STATE_YSF)
     ysfTX.process();
+#endif
 
+#if defined(MODE_P25)
   if (m_p25Enable && m_modemState == STATE_P25)
     p25TX.process();
+#endif
 
+#if defined(MODE_NXDN)
   if (m_nxdnEnable && m_modemState == STATE_NXDN)
     nxdnTX.process();
+#endif
 
+#if defined(MODE_M17)
+  if (m_m17Enable && m_modemState == STATE_M17)
+    m17TX.process();
+#endif
+
+#if defined(MODE_POCSAG)
   if (m_pocsagEnable && (m_modemState == STATE_POCSAG || pocsagTX.busy()))
     pocsagTX.process();
+#endif
 
+#if defined(MODE_AX25)
+  if (m_ax25Enable && (m_modemState == STATE_IDLE || m_modemState == STATE_FM))
+    ax25TX.process();
+#endif
+
+#if defined(MODE_FM)
   if (m_fmEnable && m_modemState == STATE_FM)
     fm.process();
+#endif
 
+#if defined(MODE_DSTAR)
   if (m_modemState == STATE_DSTARCAL)
     calDStarTX.process();
+#endif
 
+#if defined(MODE_DMR)
   if (m_modemState == STATE_DMRCAL || m_modemState == STATE_LFCAL || m_modemState == STATE_DMRCAL1K || m_modemState == STATE_DMRDMO1K)
     calDMR.process();
+#endif
 
+#if defined(MODE_FM)
+  if (m_modemState == STATE_FMCAL10K || m_modemState == STATE_FMCAL12K || m_modemState == STATE_FMCAL15K || m_modemState == STATE_FMCAL20K || m_modemState == STATE_FMCAL25K || m_modemState == STATE_FMCAL30K)
+    calFM.process();
+#endif
+
+#if defined(MODE_P25)
   if (m_modemState == STATE_P25CAL1K)
     calP25.process();
+#endif
 
+#if defined(MODE_NXDN)
   if (m_modemState == STATE_NXDNCAL1K)
     calNXDN.process();
+#endif
 
+#if defined(MODE_POCSAG)
   if (m_modemState == STATE_POCSAGCAL)
     calPOCSAG.process();
-
-  if (m_modemState == STATE_FMCAL10K || m_modemState == STATE_FMCAL12K || m_modemState == STATE_FMCAL15K || m_modemState == STATE_FMCAL20K || m_modemState == STATE_FMCAL25K ||m_modemState == STATE_FMCAL30K)
-    calFM.process();
+#endif
 
   if (m_modemState == STATE_IDLE)
     cwIdTX.process();

MMDVM.ino

@@ -28,45 +28,75 @@ bool m_dmrEnable    = true;
 bool m_ysfEnable    = true;
 bool m_p25Enable    = true;
 bool m_nxdnEnable   = true;
+bool m_m17Enable    = true;
 bool m_pocsagEnable = true;
 bool m_fmEnable     = true;
+bool m_ax25Enable   = true;
 
 bool m_duplex = true;
 
 bool m_tx  = false;
 bool m_dcd = false;
 
-CDStarRX   dstarRX;
-CDStarTX   dstarTX;
-
-CDMRIdleRX dmrIdleRX;
-CDMRRX     dmrRX;
-CDMRTX     dmrTX;
-
-CDMRDMORX  dmrDMORX;
-CDMRDMOTX  dmrDMOTX;
-
-CYSFRX     ysfRX;
-CYSFTX     ysfTX;
-
-CP25RX     p25RX;
-CP25TX     p25TX;
-
-CNXDNRX    nxdnRX;
-CNXDNTX    nxdnTX;
-
-CPOCSAGTX  pocsagTX;
-
-CFM        fm;
+#if defined(MODE_DSTAR)
+CDStarRX dstarRX;
+CDStarTX dstarTX;
 
 CCalDStarRX calDStarRX;
 CCalDStarTX calDStarTX;
-CCalDMR     calDMR;
-CCalFM      calFM;
-CCalP25     calP25;
-CCalNXDN    calNXDN;
-CCalPOCSAG  calPOCSAG;
-CCalRSSI    calRSSI;
+#endif
+
+#if defined(MODE_DMR)
+CDMRIdleRX dmrIdleRX;
+CDMRRX dmrRX;
+CDMRTX dmrTX;
+
+CDMRDMORX dmrDMORX;
+CDMRDMOTX dmrDMOTX;
+
+CCalDMR calDMR;
+#endif
+
+#if defined(MODE_YSF)
+CYSFRX ysfRX;
+CYSFTX ysfTX;
+#endif
+
+#if defined(MODE_P25)
+CP25RX p25RX;
+CP25TX p25TX;
+
+CCalP25 calP25;
+#endif
+
+#if defined(MODE_NXDN)
+CNXDNRX nxdnRX;
+CNXDNTX nxdnTX;
+
+CCalNXDN calNXDN;
+#endif
+
+#if defined(MODE_M17)
+CM17RX m17RX;
+CM17TX m17TX;
+#endif
+
+#if defined(MODE_POCSAG)
+CPOCSAGTX  pocsagTX;
+CCalPOCSAG calPOCSAG;
+#endif
+
+#if defined(MODE_FM)
+CFM    fm;
+CCalFM calFM;
+#endif
+
+#if defined(MODE_AX25)
+CAX25RX ax25RX;
+CAX25TX ax25TX;
+#endif
+
+CCalRSSI calRSSI;
 
 CCWIdTX cwIdTX;
 
@@ -85,49 +115,86 @@ void loop()
   io.process();
 
   // The following is for transmitting
+#if defined(MODE_DSTAR)
   if (m_dstarEnable && m_modemState == STATE_DSTAR)
     dstarTX.process();
+#endif
 
+#if defined(MODE_DMR)
   if (m_dmrEnable && m_modemState == STATE_DMR) {
     if (m_duplex)
       dmrTX.process();
     else
       dmrDMOTX.process();
   }
+#endif
 
+#if defined(MODE_YSF)
   if (m_ysfEnable && m_modemState == STATE_YSF)
     ysfTX.process();
+#endif
 
+#if defined(MODE_P25)
   if (m_p25Enable && m_modemState == STATE_P25)
     p25TX.process();
+#endif
 
+#if defined(MODE_NXDN)
   if (m_nxdnEnable && m_modemState == STATE_NXDN)
     nxdnTX.process();
+#endif
 
+#if defined(MODE_M17)
+  if (m_m17Enable && m_modemState == STATE_M17)
+    m17TX.process();
+#endif
+
+#if defined(MODE_POCSAG)
   if (m_pocsagEnable && (m_modemState == STATE_POCSAG || pocsagTX.busy()))
     pocsagTX.process();
+#endif
 
+#if defined(MODE_AX25)
+  if (m_ax25Enable && (m_modemState == STATE_IDLE || m_modemState == STATE_FM))
+    ax25TX.process();
+#endif
+
+#if defined(MODE_FM)
   if (m_fmEnable && m_modemState == STATE_FM)
     fm.process();
+#endif
 
+#if defined(MODE_DSTAR)
   if (m_modemState == STATE_DSTARCAL)
     calDStarTX.process();
+#endif
 
+#if defined(MODE_DMR)
   if (m_modemState == STATE_DMRCAL || m_modemState == STATE_LFCAL || m_modemState == STATE_DMRCAL1K || m_modemState == STATE_DMRDMO1K)
     calDMR.process();
+#endif
 
+#if defined(MODE_FM)
   if (m_modemState == STATE_FMCAL10K || m_modemState == STATE_FMCAL12K || m_modemState == STATE_FMCAL15K || m_modemState == STATE_FMCAL20K || m_modemState == STATE_FMCAL25K || m_modemState == STATE_FMCAL30K)
     calFM.process();
+#endif
 
+#if defined(MODE_P25)
   if (m_modemState == STATE_P25CAL1K)
     calP25.process();
+#endif
 
+#if defined(MODE_NXDN)
   if (m_modemState == STATE_NXDNCAL1K)
     calNXDN.process();
+#endif
 
+#if defined(MODE_POCSAG)
   if (m_modemState == STATE_POCSAGCAL)
     calPOCSAG.process();
+#endif
 
   if (m_modemState == STATE_IDLE)
     cwIdTX.process();
 }
+

Makefile

@@ -133,12 +133,18 @@ DEFS_PI_F722=-DUSE_HAL_DRIVER -DSTM32F722xx -DSTM32F7XX -DSTM32F722_PI -DHSE_VAL
 DEFS_F7M=-DUSE_HAL_DRIVER -DSTM32F722xx -DSTM32F7XX -DSTM32F722_F7M -DHSE_VALUE=$(OSC) -DMADEBYMAKEFILE
 # MMDVM_RPT_Hat F0DEI, DB9MAT, DF2ET board:
 DEFS_RPT_HAT=-DUSE_HAL_DRIVER -DSTM32F722xx -DSTM32F7XX -DSTM32F722_RPT_HAT -DHSE_VALUE=$(OSC) -DMADEBYMAKEFILE
-# STM32F4 DVM board:
+# RB STM32F4_DVM board:
 DEFS_DVM=-DUSE_STDPERIPH_DRIVER -DSTM32F4XX -DSTM32F446xx -DSTM32F4_DVM -DHSE_VALUE=$(OSC) -DMADEBYMAKEFILE
+# RB STM32F7 DVM board:
+DEFS_DVM722=-DUSE_HAL_DRIVER -DSTM32F722xx -DSTM32F7XX -DSTM32F7_DVM -DHSE_VALUE=$(OSC) -DMADEBYMAKEFILE
 # MMDVM_RPT_Hat BG4TGO, BG5HHP board:
 DEFS_RPT_HAT_TGO=-DUSE_STDPERIPH_DRIVER -DSTM32F4XX -DSTM32F40_41xxx -DSTM32F4_RPT_HAT_TGO -DHSE_VALUE=$(OSC) -DMADEBYMAKEFILE
 # DRCC_DVM BG7NQF board:
 DEFS_DRCC_DVM=-DUSE_STDPERIPH_DRIVER -DSTM32F4XX -DSTM32F446xx -DDRCC_DVM -DHSE_VALUE=$(OSC) -DMADEBYMAKEFILE
+# WA0EDA F405 MTR2K, MASTR3 board:
+DEFS_EDA_405=-DUSE_STDPERIPH_DRIVER -DSTM32F4XX -DSTM32F40_41xxx -DSTM32F4_EDA_405 -DHSE_VALUE=$(OSC) -DMADEBYMAKEFILE
+# WA0EDA F446 MTR2K, MASTR3 board:
+DEFS_EDA_446=-DUSE_STDPERIPH_DRIVER -DSTM32F4XX -DSTM32F446xx -DSTM32F4_EDA_446 -DHSE_VALUE=$(OSC) -DMADEBYMAKEFILE
 
 
 # Build compiler flags
@@ -218,17 +224,41 @@ f767: LDFLAGS+=$(LDFLAGS_F767)
 f767: release_f7
 
 dvm: GitVersion.h
-dvm: CFLAGS+=$(CFLAGS_F4) $(DEFS_DVM)
-dvm: CXXFLAGS+=$(CXXFLAGS_F4) $(DEFS_DVM)
+dvm: CFLAGS+=$(CFLAGS_F4) $(DEFS_DVM) -DDRCC_DVM_446
+dvm: CXXFLAGS+=$(CXXFLAGS_F4) $(DEFS_DVM) -DDRCC_DVM_446
 dvm: LDFLAGS+=$(LDFLAGS_F4)
 dvm: release_f4
 
+dvm722: GitVersion.h
+dvm722: CFLAGS+=$(CFLAGS_F7) $(DEFS_DVM722) -DDRCC_DVM_722
+dvm722: CXXFLAGS+=$(CXXFLAGS_F7) $(DEFS_DVM722) -DDRCC_DVM_722
+dvm722: LDFLAGS+=$(LDFLAGS_F722)
+dvm722: release_f7
+
 drcc_nqf: GitVersion.h
 drcc_nqf: CFLAGS+=$(CFLAGS_F4) $(DEFS_DRCC_DVM) -DDRCC_DVM_NQF
 drcc_nqf: CXXFLAGS+=$(CXXFLAGS_F4) $(DEFS_DRCC_DVM) -DDRCC_DVM_NQF
 drcc_nqf: LDFLAGS+=$(LDFLAGS_F4)
 drcc_nqf: release_f4
 
+hhp446: GitVersion.h
+hhp446: CFLAGS+=$(CFLAGS_F4) $(DEFS_DRCC_DVM) -DDRCC_DVM_HHP446
+hhp446: CXXFLAGS+=$(CXXFLAGS_F4) $(DEFS_DRCC_DVM) -DDRCC_DVM_HHP446
+hhp446: LDFLAGS+=$(LDFLAGS_F4)
+hhp446: release_f4
+
+eda405: GitVersion.h
+eda405: CFLAGS+=$(CFLAGS_F4) $(DEFS_EDA_405)
+eda405: CXXFLAGS+=$(CXXFLAGS_F4) $(DEFS_EDA_405)
+eda405: LDFLAGS+=$(LDFLAGS_F4)
+eda405: release_f4
+
+eda446: GitVersion.h
+eda446: CFLAGS+=$(CFLAGS_F4) $(DEFS_EDA_446)
+eda446: CXXFLAGS+=$(CXXFLAGS_F4) $(DEFS_EDA_446)
+eda446: LDFLAGS+=$(LDFLAGS_F4)
+eda446: release_f4
+
 release_f4: $(BINDIR)
 release_f4: $(OBJDIR_F4)
 release_f4: $(BINDIR)/$(BINHEX_F4)
@@ -338,27 +368,27 @@ endif
 deploy-pi:
 ifneq ($(wildcard /usr/local/bin/stm32flash),)
 	-/usr/local/bin/stm32flash -i 20,-21,21:-20,21 /dev/ttyAMA0
-	-/usr/local/bin/stm32ld /dev/ttyAMA0 57600 bin/$(BINBIN_F4)
-	/usr/local/bin/stm32flash -v -w bin/$(BINBIN_F4) -g 0x0 -R -c /dev/ttyAMA0
+	/usr/local/bin/stm32flash -v -w bin/$(BINBIN_F4) -g 0x0 -R /dev/ttyAMA0
 endif
 
 ifneq ($(wildcard /usr/bin/stm32flash),)
 	-/usr/bin/stm32flash -i 20,-21,21:-20,21 /dev/ttyAMA0
-	-/usr/bin/stm32ld /dev/ttyAMA0 57600 bin/$(BINBIN_F4)
-	/usr/bin/stm32flash -v -w bin/$(BINBIN_F4) -g 0x0 -R -c /dev/ttyAMA0
+	/usr/bin/stm32flash -v -w bin/$(BINBIN_F4) -g 0x0 -R /dev/ttyAMA0
 endif
 
 deploy-f4m: deploy-pi
 deploy-dvm: deploy-pi
+deploy-eda405: deploy-pi
+deploy-eda446: deploy-pi
 
 deploy-pi-f7:
 ifneq ($(wildcard /usr/local/bin/stm32flash),)
 	-/usr/local/bin/stm32flash -i 20,-21,21:-20,21 /dev/ttyAMA0
-	/usr/local/bin/stm32flash -v -w bin/$(BINBIN_F7) -g 0x0 -R -c /dev/ttyAMA0
+	/usr/local/bin/stm32flash -v -w bin/$(BINBIN_F7) -g 0x0 -R /dev/ttyAMA0
 
 else ifneq ($(wildcard /usr/bin/stm32flash),)
 	-/usr/bin/stm32flash -i 20,-21,21:-20,21 /dev/ttyAMA0
-	/usr/bin/stm32flash -v -w bin/$(BINBIN_F7) -g 0x0 -R -c /dev/ttyAMA0
+	/usr/bin/stm32flash -v -w bin/$(BINBIN_F7) -g 0x0 -R /dev/ttyAMA0
 endif
 
 deploy-f7m:   deploy-pi-f7

Makefile.Arduino

@@ -1,5 +1,5 @@
 #!/usr/bin/make
-# makefile for the arduino due (works with arduino IDE 1.6.11)
+# makefile for the arduino due (works with arduino IDE 1.6.12)
 #
 # The original file can be found at https://github.com/pauldreik/arduino-due-makefile
 #
@@ -34,7 +34,7 @@ OBJCOPY:=$(ADIR)/packages/arduino/tools/arm-none-eabi-gcc/4.8.3-2014q1/bin/arm-n
 
 C:=$(CC)
 #SAM:=arduino/sam/
-SAM:=$(ADIR)/packages/arduino/hardware/sam/1.6.11
+SAM:=$(ADIR)/packages/arduino/hardware/sam/1.6.12
 #CMSIS:=arduino/sam/system/CMSIS/
 #LIBSAM:=arduino/sam/system/libsam
 TMPDIR:=$(PWD)/build

NXDNRX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2018 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2018,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_NXDN)
+
 #include "Globals.h"
 #include "NXDNRX.h"
 #include "Utils.h"
@@ -403,3 +406,5 @@ void CNXDNRX::writeRSSIData(uint8_t* data)
   m_rssiCount = 0U;
 }
 
+#endif
+

NXDNRX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017,2018 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2018,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,10 +16,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_NXDN)
+
 #if !defined(NXDNRX_H)
 #define  NXDNRX_H
 
-#include "Config.h"
 #include "NXDNDefines.h"
 
 enum NXDNRX_STATE {
@@ -67,3 +70,5 @@ private:
 
 #endif
 
+#endif
+

NXDNTX.cpp

@@ -18,6 +18,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_NXDN)
+
 #include "Globals.h"
 #include "NXDNTX.h"
 
@@ -81,7 +84,8 @@ void CNXDNTX::process()
       m_poBuffer[m_poLen++] = NXDN_PREAMBLE[2U];
     } else {
       for (uint8_t i = 0U; i < NXDN_FRAME_LENGTH_BYTES; i++) {
-        uint8_t c = m_buffer.get();
+        uint8_t c = 0U;
+        m_buffer.get(c);
         m_poBuffer[m_poLen++] = c;
       }
     }
@@ -122,7 +126,7 @@ void CNXDNTX::process()
   }
 }
 
-uint8_t CNXDNTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CNXDNTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != (NXDN_FRAME_LENGTH_BYTES + 1U))
     return 4U;
@@ -199,3 +203,6 @@ void CNXDNTX::setParams(uint8_t txHang)
 {
   m_txHang = txHang * 600U;
 }
+
+#endif
+

NXDNTX.h

@@ -16,18 +16,20 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_NXDN)
+
 #if !defined(NXDNTX_H)
 #define  NXDNTX_H
 
-#include "Config.h"
-
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CNXDNTX {
 public:
   CNXDNTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();
 
@@ -38,7 +40,7 @@ public:
   void setParams(uint8_t txHang);
 
 private:
-  CSerialRB                        m_buffer;
+  CRingBuffer<uint8_t>                        m_buffer;
   arm_fir_interpolate_instance_q15 m_modFilter;
   arm_fir_instance_q15             m_sincFilter;
   q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare
@@ -55,3 +57,6 @@ private:
 };
 
 #endif
+
+#endif
+

P25RX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2018 by Bryan Biedenkapp <gatekeep@gmail.com>
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -18,6 +18,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_P25)
+
 #include "Globals.h"
 #include "P25RX.h"
 #include "Utils.h"
@@ -535,3 +538,6 @@ void CP25RX::writeRSSILdu(uint8_t* ldu)
   m_rssiAccum = 0U;
   m_rssiCount = 0U;
 }
+
+#endif
+

P25RX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2018 by Bryan Biedenkapp <gatekeep@gmail.com>
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -17,10 +17,13 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_P25)
+
 #if !defined(P25RX_H)
 #define  P25RX_H
 
-#include "Config.h"
 #include "P25Defines.h"
 
 enum P25RX_STATE {
@@ -72,3 +75,6 @@ private:
 };
 
 #endif
+
+#endif
+

P25TX.cpp

@@ -18,6 +18,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_P25)
+
 #include "Globals.h"
 #include "P25TX.h"
 
@@ -75,9 +78,11 @@ void CP25TX::process()
       for (uint16_t i = 0U; i < m_txDelay; i++)
         m_poBuffer[m_poLen++] = P25_START_SYNC;
     } else {
-      uint8_t length = m_buffer.get();
+      uint8_t length;
+      m_buffer.get(length);
       for (uint8_t i = 0U; i < length; i++) {
-        uint8_t c = m_buffer.get();
+        uint8_t c = 0U;
+        m_buffer.get(c);
         m_poBuffer[m_poLen++] = c;
       }
     }
@@ -118,7 +123,7 @@ void CP25TX::process()
   }
 }
 
-uint8_t CP25TX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CP25TX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length < (P25_TERM_FRAME_LENGTH_BYTES + 1U))
     return 4U;
@@ -196,3 +201,6 @@ void CP25TX::setParams(uint8_t txHang)
 {
   m_txHang = txHang * 1200U;
 }
+
+#endif
+

P25TX.h

@@ -16,18 +16,20 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_P25)
+
 #if !defined(P25TX_H)
 #define  P25TX_H
 
-#include "Config.h"
-
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CP25TX {
 public:
   CP25TX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();
 
@@ -38,7 +40,7 @@ public:
   void setParams(uint8_t txHang);
 
 private:
-  CSerialRB                        m_buffer;
+  CRingBuffer<uint8_t>                        m_buffer;
   arm_fir_interpolate_instance_q15 m_modFilter;
   arm_fir_instance_q15             m_lpFilter;
   q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare
@@ -55,3 +57,6 @@ private:
 };
 
 #endif
+
+#endif
+

POCSAGTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2018 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2018,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -17,6 +17,9 @@
  */
 
 #include "Config.h"
+
+#if defined(MODE_POCSAG)
+
 #include "Globals.h"
 #include "POCSAGTX.h"
 
@@ -61,7 +64,8 @@ void CPOCSAGTX::process()
         m_poBuffer[m_poLen++] = POCSAG_SYNC;
     } else {
       for (uint8_t i = 0U; i < POCSAG_FRAME_LENGTH_BYTES; i++) {
-        uint8_t c = m_buffer.get();
+        uint8_t c = 0U;
+        m_buffer.get(c);
         m_poBuffer[m_poLen++] = c;
       }
     }
@@ -95,7 +99,7 @@ bool CPOCSAGTX::busy()
     return false;
 }
 
-uint8_t CPOCSAGTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CPOCSAGTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != POCSAG_FRAME_LENGTH_BYTES)
     return 4U;
@@ -147,3 +151,5 @@ uint8_t CPOCSAGTX::getSpace() const
   return m_buffer.getSpace() / POCSAG_FRAME_LENGTH_BYTES;
 }
 
+#endif
+

POCSAGTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015-2019 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015-2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,18 +16,20 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "Config.h"
+
+#if defined(MODE_POCSAG)
+
 #if !defined(POCSAGTX_H)
 #define  POCSAGTX_H
 
-#include "Config.h"
-
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CPOCSAGTX {
 public:
   CPOCSAGTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void writeByte(uint8_t c);
 
@@ -40,7 +42,7 @@ public:
   bool busy();
 
 private:
-  CSerialRB            m_buffer;
+  CRingBuffer<uint8_t>            m_buffer;
   arm_fir_instance_q15 m_modFilter;
   q15_t                m_modState[170U];     // NoTaps + BlockSize - 1, 6 + 160 - 1 plus some spare
   uint8_t              m_poBuffer[200U];
@@ -51,3 +53,5 @@ private:
 
 #endif
 
+#endif
+